As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perov...As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perovskites are showing the potential to make distinct marks in the fields of electronics,optoelectronics and photonics.The so-called perovskite quantum dots(PQDs)not only possess the most important features of LHP materials,i.e.,the unusual high defect tolerance,but also demonstrate clear quantum size effects,along with exhibiting desirable optoelectronic properties such as near perfect photoluminescent quantum yield,multiple exciton generation and slow hot-carrier cooling.Here,we review the advantageous properties of these nanoscale perovskites and survey the prospects for diverse applications which include lightemitting devices,solar cells,photocatalysts,lasers,detectors and memristors,emphasizing the distinct superiorities as well as the challenges.展开更多
All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading ...All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.展开更多
This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the ...This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron beam.Then,we simulate the spatial distribution of the electron beams in CsPbX_(3)films.Combined with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented.This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.展开更多
Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance ...Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance for the colloidal stability and property tuning of PQDs, while their highly dynamic binding nature not only impedes further efficiency improvement of PQD-based solar cells but also induces intrinsic instability. Tremendous efforts have been made in ligand engineering with good hopes to solve such challenging issues in the past few years. In this review, we first present a fundamental understanding of the role of surface ligands in PQDs, followed by a brief discussion and classification of various ligands that have the potential for improving the electronic coupling and stability of PQD solids. We then provide a critical overview of recent advances in ligand engineering including the strategies of in-situ ligand engineering, postsynthesis/-deposition ligand-exchange, and interfacial engineering, and discuss their impacts on changing the efficiency and stability of perovskite QD solar cells(QDSCs). Finally, we give our perspectives on the future directions of ligand engineering towards more efficient and stable perovskite QDSCs.展开更多
Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs.However,they e...Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs.However,they exhibit low moisture stability at room humidity(20-30%)owing to many surface defect sites generated by inefficient ligand exchange process.These surface traps must be re-passivated to improve both charge transport ability and moisture stability.To address this issue,PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect passivation.Conventional organic semiconductors are typically low-dimensional(1D and 2D)and prone to excessive self-aggregation,which limits chemical interaction with PQDs.In this work,we designed a new 3D star-shaped semiconducting material(Star-TrCN)to enhance the compatibility with PQDs.The robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental validation.The Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI_(3)-PQDs via reduced surface trap states and suppressed moisture penetration.As a result,the resultant devices not only achieve remarkable device stability over 1000 h at 20-30%relative humidity,but also boost power conversion efficiency up to 16.0%via forming a cascade energy band structure.展开更多
Photodetectors based on amorphous InGaZnO(a-IGZO)thin film transistor(TFT)and halide perovskites have attracted attention in recent years.However,such a stack assembly of a halide perovskite layer/an a-IGZO channel,ev...Photodetectors based on amorphous InGaZnO(a-IGZO)thin film transistor(TFT)and halide perovskites have attracted attention in recent years.However,such a stack assembly of a halide perovskite layer/an a-IGZO channel,even with an organic semiconductor film inserted between them,easily has a very limited photoresponsivity.In this article,we investigate photoresponsive characteristics of TFTs by using CsPbX3(X=Br or I)quantum dots(QDs)embedded into the a-IGZO channel,and attain a high photoresponsivity over 10^3A·W^-1,an excellent detectivity in the order of 10^16 Jones,and a light-to-dark current ratio up to 10^5 under visible lights.This should be mainly attributed to the improved transfer efficiency of photoelectrons from the QDs to the a-IGZO channel.Moreover,spectrally selective photodetection is demonstrated by introducing halide perovskite QDs with different bandgaps.Thus,this work provides a novel strategy of device structure optimization for significantly improving the photoresponsive characteristics of TFT photodetectors.展开更多
CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improv...CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.展开更多
Perovskite quantum dots(PQDs) possess remarkable optical properties, such as tunable photoluminescence(PL) emission spectra, narrow full width at half maximum(FWHM) and high PL quantum yield(QY), endowing the PQDs gre...Perovskite quantum dots(PQDs) possess remarkable optical properties, such as tunable photoluminescence(PL) emission spectra, narrow full width at half maximum(FWHM) and high PL quantum yield(QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen(FAPbX_(3), X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene(core) and polymethyl methacrylate(shell) coated FAPbCl_(3) QDs(abbreviated as PS/FAPbCl_(3)/PMMA, hereinafter), green-emissive PS/FAPbBr_(3)/PMMA and redemissive PS/FAPbI_(3)/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover,the PS/FAPbBr_(3)/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green-and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.展开更多
Micro/nanoscale photonic barcodes hold great potential for broad applications in items tracking,mul-tiplexed bioassays and anti-counterfeiting.The ever-increasing demand in advanced anti-counterfeiting applications ca...Micro/nanoscale photonic barcodes hold great potential for broad applications in items tracking,mul-tiplexed bioassays and anti-counterfeiting.The ever-increasing demand in advanced anti-counterfeiting applications calls for micro/nanoscale barcodes with accurate recognition,large encoding capacity and high security level.Here,we proposed a strategy to construct the dual-stimuli responsive photonic barcodes based on the perovskite quantum dots(PQDs)doped polymer whispering-gallery-mode(WGM)microcavities via swelling-deswelling method.Benefiting from the well-defined spherical microcavities,the photoluminescence(PL)spectra of as-prepared composites exhibit a series of sharp peaks characteristics resulting from the effective WGM modulation,which constitutes the fingerprint of a specific resonator and thus allows a definition of photonic barcodes.On this basis,we achieved responsive photonic barcodes based on the volatile polar-solvent-controlled luminescence in the mi-crospheres benefitting from the space-confined microcavities and the ionic feature of the PQDs.More-over,the light-controlled photonic barcodes have further been acquired through reversibly regulating the inactivation and activation of the energy transfer(ET)process between the PQDs and photochromic dyes.The well-established protocols of PQDs@WGM enable the development of distinct responsive barcodes with multi-responsive features,which will pave an avenue to new types of flexible WGM-based components for optical data recording and security labels.展开更多
Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel...Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel behavior,they have intrinsic stability issues.In this study,an effectively silane barrier-capped quantum dot(QD@APDEMS)is thinly applied onto a bulk perovskite photosensitive layer for use in photodetectors.QD@APDEMS is synthesized with a silane ligand with hydrophobic CH_(3)-terminal groups,resulting in excellent dispersibility and durability to enable effective coating.The introduction of the QD@APDEMS layer results in the formation of a lowdefect perovskite film with enlarged grains.This is attributed to the grain boundary interconnection effect via interaction between the functional groups of QD@APDEMS and uncoordinated Pb^(2+)in grain boundaries.By passivating the grain boundaries,where various trap sites are distributed,hole chargecarrier injection and shunt leakage can be suppressed.Also,from the energy point of view,the deep highest occupied molecular orbital(HOMO)level of QD@APDEMS can work as a hole charge injection barrier.Improved charge dynamics(generation,transfer,and recombination properties)and reduced trap density of QD@APDEMS are demonstrated.When this perovskite film is used in a photodetector,the device performance(especially the detectivity)stands out among existing perovskites evaluated for energy sensing device applications.展开更多
Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)PQDs has been recognized as one of the promising candidates.However,the low photoluminescence quantum yields...Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)PQDs has been recognized as one of the promising candidates.However,the low photoluminescence quantum yields(PLQYs)hinder its practical application in optoelectronic devices.Here,w e successfully prepared Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs with effective white light-emission by modified ligandassisted recrystallization method.The realization of white light-emission is attributed to the broadband blue emission of excitons and the red emission(^(4)G_(5/2)-^(6)HJ(J=5/2,7/2,9/2))of Sm^(3+)ions for Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs.More importantly,compared with the undoped Cs_(3)Bi_(2)Br_(g)PQDs,the PLQYs of Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs are improved from 10.9%to 20.8%,and the anti-water stability is also obviously improved.Finally,the Sm^(3+)ions doped PQDs based white light-emitting diodes(LEDs)with luminous efficiency of 12.6 lm/W were explored,which indicates that there is a potential prospect of lead-free PQDs in white light lighting application.展开更多
Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) quantum dots(QDs)mesoporous hollow nanocomposites with good luminescent properties and high stability were built.Among which,the hollow Gd_(2)O_(3):Eu^(3+)spheres and CsPbBr_(3) QDs were...Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) quantum dots(QDs)mesoporous hollow nanocomposites with good luminescent properties and high stability were built.Among which,the hollow Gd_(2)O_(3):Eu^(3+)spheres and CsPbBr_(3) QDs were prepared by urea homogeneous precipitation and hot-injection method,respectively.Finally,the Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs shell-core compounds were constructed through mechanical stirring.The structure,morphology,stability and luminescent properties were studied by Fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry/thermogravity(DSC/TG),X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),photoluminescence excitation/photoluminescence(PLE/PL)and life decay tools.Compared to the original CsPbBr_(3) QDs,Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs display better photostability,thermal stability and current stability.The resulting Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs composite exhibits good yellow emission.The Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs mixed silicone resin was directly coated on the blue LED chip,then the w-LED device with the color coordinate of(0.31,0.32)was successfully assembled.The Gd_(2) O_(3):Eu^(3+)@CsPbBr_(3) QDs compounds with excellent luminescent properties and stability are expected to be widely used in lighting and display areas.展开更多
The stability of lead halide perovskite quantum dots (PQDs) was improved by embedding them in carboxybenzene microcrystals. The resulting needle-shaped mixed microcrystals preserved the strong photoluminescence of t...The stability of lead halide perovskite quantum dots (PQDs) was improved by embedding them in carboxybenzene microcrystals. The resulting needle-shaped mixed microcrystals preserved the strong photoluminescence of the PQDs. Compared with previously reported polystyrene-encapsulated PQDs, the carboxybenzene crystals were robust and protected the dots from moisture and photodegradation. The enhanced stability was attributed to the tight matrix of carboxybenzene microcrystals, which protected the PQDs from moisture. This versatile strategy protected various QDs, including all-inorganic PQDs and chalcogenide QDs (e.g., CdSe/ZnS QDs and CuInS/ZnS QDs). It provides a facile and versatile method of protecting PQDs and may enable applications in solid-state systems with high color quality requirements such as displays, lasers, and light emitting diodes.展开更多
In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor poly...In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor polyhedral oligomeric silsesquioxane-perovskite quantum dots(cDNA-POSSPQDs)were used as encoded probes and combined with dual-stirring-bar-assisted signal amplification for pathogen quantification.In this system,bar 1 was labeled with the S.T.and V.P.Apts,and then bar 2 was functionalized with cDNA-POSS-PQDs.When S.T.and V.P.were introduced,pathogen-Apt complexes would form and be released into the supernatant from bar 1.Under agitation,the two complexes reached bar 2 and subsequently reacted with cDNA-POSS-PQDs,which were immobilized on MXene.Then,the encoded probes would be detached from bar 2 to generate FL signals in the supernatant.Notably,the pathogens can resume their free state and initiate next cycle.They swim between the two bars,and the FL signals can be gradually enhanced to maximum after several cycles.The FL signals from released encoded probes can be used to detect the analytes.In particular,live pathogens can be distinguished from dead ones by using an assay.The detection limits and linear range for S.T.and V.P.were 30 and 10 CFU/mL and 10^(2) -10^(6) CFU/mL,respectively.Therefore,this assay has broad application potential for simultaneous on-site detection of various live pathogenic bacteria in water.展开更多
Although laser pumping using electron beam(EB)has high transient power output and easy modulation based on perovskite quantum dot(PQD)film,its lasing emitting direction is the same as the pumped EB's direction.Thu...Although laser pumping using electron beam(EB)has high transient power output and easy modulation based on perovskite quantum dot(PQD)film,its lasing emitting direction is the same as the pumped EB's direction.Thus,realizing the conventional direct device structure through the film lasing mechanism is extremely difficult.Therefore,using the random lasing principle,herein,we proposed a corona modulation device structure based on PQDs random laser pumped using an EB.We discussed and stimulated the optimized designed method of the device in terms of parameters of the electronic optical device and the utilization ratio of output power and its modulation extinction ratio,respectively.According to the simulation results,this type of device structure can effectively satisfy the new random lasing mechanism in terms of high-speed and high-power modulation.展开更多
Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-P6rot cavity-forming nanowires.We demonstrate the direct observation of lasing from transverse electromagnetic(TEM)modes w...Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-P6rot cavity-forming nanowires.We demonstrate the direct observation of lasing from transverse electromagnetic(TEM)modes with a long coherence time-9.5ps in coupled CsPbBr_(3) quantum dots,which dispense with an external cavity resonator and show how the wavelength of the modes can be controlled via two independent tuning-mechanisms.Controlling the pump power allowed us tofine-tune the TEM mode structure to the emission wavelength,thus providing a degree of control over the properties of the lasing signal.The temperature-tuning provided an additional degree of control over the wavelength of the lasing peak,importantly,maintained a constant full width at half maximum(FWHM)over the entire tuning range without mode-hopping.展开更多
Perovskite quantum dots(PQDs)are new class of optoelectronic materials,which have been widely studied for their extraordinary physical properties.Attempts to develop these materials are tending to make their fabricati...Perovskite quantum dots(PQDs)are new class of optoelectronic materials,which have been widely studied for their extraordinary physical properties.Attempts to develop these materials are tending to make their fabrication much controllable and extend their values in different areas.Here,we present a novel strategy for one-step in situ synthesis of PQD-encapsulated barcode particles with the assistance of microfluidic technique.By changing the halide ratio in perovskite precursor solutions that emulsified in microfluidic devices,a series of PQDs with different colors have been successfully fabricated,which made them ideal materials as barcodes.Because of the stable encapsulation of ethyleneglycol dimethacrylate(EGDMA)resin,the PQD-encapsulated barcode particles were with no cytotoxicity and could be anti-quenched.It was demonstrated for the first time that the PQD-encapsutated barcode particles by microfluidics were valuable for multiplex biomolecular encoding and assays.These features indicate that the PQD-encapsutated barcode particles by microfluidics are ideal for many practical applications and have a broad prospect in biomedical field.展开更多
Formamidinium lead triiodide(FAPbI_(3))perovskite quantum dots(PQDs)show great advantages in photovoltaic applications due to their ideal bandgap energy,high stability and solution processability.The anti-solvent used...Formamidinium lead triiodide(FAPbI_(3))perovskite quantum dots(PQDs)show great advantages in photovoltaic applications due to their ideal bandgap energy,high stability and solution processability.The anti-solvent used for the post-treatment of FAPbI_(3) PQD solid flms signifcantly afects the surface chemistry of the PQDs,and thus the vacancies caused by surface ligand removal inhibit the optoelectronic properties and stability of PQDs.Here,we study the efects of diferent anti-solvents with diferent polarities on FAPbI_(3) PQDs and select a series of organic molecules for surface passivation of PQDs.The results show that methyl acetate could efectively remove surface ligands from the PQD surface without destroying its crystal structure during the post-treatment.The benzamidine hydrochloride(PhFACl)applied as short ligands of PQDs during the post-treatment could fll the A-site and X-site vacancies of PQDs and thus improve the electronic coupling of PQDs.Finally,the PhFACl-based PQD solar cell(PQDSC)achieves a power conversion efciency of 6.4%,compared to that of 4.63%for the conventional PQDSC.This work provides a reference for insights into the surface passivation of PQDs and the improvement in device performance of PQDSCs.展开更多
Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite qua...Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite quantum dots(PeQDs)as active layer.Typical ZnO thin film transistors did not show a photocurrent under visible light illumination.However,ZnO TFTs decorated with PeQDs exhibited enhanced photocurrent upon exposure to visible light.The device had a responsivity of 567 A/W(617 A/W),a high detectivity of 6.59×10^(13)Jones(1.85×10^(14)J)and a high sensitivity of 10^(7)(10^(8))under green(blue)light at a low drain voltage of 0.1 V.The high photo-responsivity and detectivity under green light resulted from the combination of short ligands in the QDs films and the high mobility of the spray coated ZnO films.Those results are relevant for the development of low cost and low energy consumption phototransistors working in the visible range.展开更多
Perovskite quantum dots(PeQDs)are considered potential display materials due to their high color purity,high photoluminescence quantum yield(PLQY),low cost and easy film casting.In this work,a novel electroluminescenc...Perovskite quantum dots(PeQDs)are considered potential display materials due to their high color purity,high photoluminescence quantum yield(PLQY),low cost and easy film casting.In this work,a novel electroluminescence(EL)device consisting of the interface layer of long alkyl-based oleylammonium bromide(OAmBr),which passivates the surface defects of PeQDs and adjusts the carrier transport properties,was designed.The PLQY of the OAmBr/PeQD bilayer was significantly improved.A high-performance EL device with the structure of indium tin oxide/poly(3,4-ethylenedioxythiophene)polystyrene sulfonate/poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)/OAmBr/PeQDs/2,2′,2′′-(1,3,5-benzinetriyl)-tris(1-phenyl-1H benzimidazole)/LiF/Al was constructed using a spin-coating method.A peak external quantum efficiency(EQE)of 16.5%at the emission wavelength of 646 nm was obtained.Furthermore,an efficient matrix EL device was fabricated using an inkjet printing method.A high-quality PeQD matrix film was obtained by introducing small amounts of polybutene into the PeQDs to improve the printing process.The EQE reached 9.6%for the matrix device with 120 pixels per inch and the same device structure as that of the spin-coating one.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52102266,12204167)the China Postdoctoral Science Foundation(2020M680861)+4 种基金the support from the Department of Science and Technology-Science and Engineering Research Board(DST-SERB),Government of India(project no.SRG/2020/000258)CSIR-Indian Institute of Chemical Technology,Hyderabadsupported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022R1A5A1032539,2022R1C1C1008282)Industrial Strategic Technology Development Program-Alchemist Project(1415180859,Chiral perovskite LED smart contact lens based hyper vision metaverse)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)Korea Evaluation Institute of Industrial Technology(KEIT,Korea).
文摘As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perovskites are showing the potential to make distinct marks in the fields of electronics,optoelectronics and photonics.The so-called perovskite quantum dots(PQDs)not only possess the most important features of LHP materials,i.e.,the unusual high defect tolerance,but also demonstrate clear quantum size effects,along with exhibiting desirable optoelectronic properties such as near perfect photoluminescent quantum yield,multiple exciton generation and slow hot-carrier cooling.Here,we review the advantageous properties of these nanoscale perovskites and survey the prospects for diverse applications which include lightemitting devices,solar cells,photocatalysts,lasers,detectors and memristors,emphasizing the distinct superiorities as well as the challenges.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB3800101 and 2022YFE0110300)National Natural Science Foundation of China (No. U19A2089, 52261145696, 52073198, 92163114, and 22161142003)+3 种基金Natural Science Foundation of Jiangsu Province (BK20211598)“111” projectthe Young Elite Scientist Sponsorship Program by CASTCollaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University。
文摘All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.
基金funded by the National Natural Science Foundation of China(Grant Nos.61905026,61703057,11874091,and 61905023)the National Key Research and Development Program of China(Grant No.2018YFB1800303)+2 种基金Construction Project of Key Laboratory of Astronomical Optics Technology of Chinese Academy of Sciences(Grant No.CAS-KLAOTKF201803)Chongqing Natural Science Foundation of China(Grant No.CSTC2021JCYJMSXMX0500)Foundation Project of Jilin Province,China(Grant Nos.20210402067GH,JJKH20210830KJ,JJKH20210800KJ,20200301065RQ,20190201188JC,and2019C043-6)。
文摘This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron beam.Then,we simulate the spatial distribution of the electron beams in CsPbX_(3)films.Combined with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented.This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.
基金the financial support from the Australian Research Council (ARC) Laureate Fellowship (FL190100139)the ARC Discovery Project (DP200101900)+3 种基金the CRC-P programsthe funding support from the ARC through Discovery Early Career Researcher Award Fellowship (DE190101351)the Discovery Project (DP190102507)the financial support from University of Queensland Research Training Scholarship。
文摘Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance for the colloidal stability and property tuning of PQDs, while their highly dynamic binding nature not only impedes further efficiency improvement of PQD-based solar cells but also induces intrinsic instability. Tremendous efforts have been made in ligand engineering with good hopes to solve such challenging issues in the past few years. In this review, we first present a fundamental understanding of the role of surface ligands in PQDs, followed by a brief discussion and classification of various ligands that have the potential for improving the electronic coupling and stability of PQD solids. We then provide a critical overview of recent advances in ligand engineering including the strategies of in-situ ligand engineering, postsynthesis/-deposition ligand-exchange, and interfacial engineering, and discuss their impacts on changing the efficiency and stability of perovskite QD solar cells(QDSCs). Finally, we give our perspectives on the future directions of ligand engineering towards more efficient and stable perovskite QDSCs.
基金This work was supported by National Research Foundation of Korea(NRF)grants funded by Ministry of Science and ICT(MSIT)(Nos.2021R1A2C3004420,2022M3J1A1085282,2020R1C1C1012256 and 2020R1C1C1003214)the NRF of Korea grant funded by the Korean Government(NRF-2019-Global Ph.D.Fellowship Program.
文摘Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs.However,they exhibit low moisture stability at room humidity(20-30%)owing to many surface defect sites generated by inefficient ligand exchange process.These surface traps must be re-passivated to improve both charge transport ability and moisture stability.To address this issue,PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect passivation.Conventional organic semiconductors are typically low-dimensional(1D and 2D)and prone to excessive self-aggregation,which limits chemical interaction with PQDs.In this work,we designed a new 3D star-shaped semiconducting material(Star-TrCN)to enhance the compatibility with PQDs.The robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental validation.The Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI_(3)-PQDs via reduced surface trap states and suppressed moisture penetration.As a result,the resultant devices not only achieve remarkable device stability over 1000 h at 20-30%relative humidity,but also boost power conversion efficiency up to 16.0%via forming a cascade energy band structure.
基金Project supported by the National Natural Science Foundation of China(Grant No.61874029)the National Key Technologies R&D Program of China(Grant No.2015ZX02102-003).
文摘Photodetectors based on amorphous InGaZnO(a-IGZO)thin film transistor(TFT)and halide perovskites have attracted attention in recent years.However,such a stack assembly of a halide perovskite layer/an a-IGZO channel,even with an organic semiconductor film inserted between them,easily has a very limited photoresponsivity.In this article,we investigate photoresponsive characteristics of TFTs by using CsPbX3(X=Br or I)quantum dots(QDs)embedded into the a-IGZO channel,and attain a high photoresponsivity over 10^3A·W^-1,an excellent detectivity in the order of 10^16 Jones,and a light-to-dark current ratio up to 10^5 under visible lights.This should be mainly attributed to the improved transfer efficiency of photoelectrons from the QDs to the a-IGZO channel.Moreover,spectrally selective photodetection is demonstrated by introducing halide perovskite QDs with different bandgaps.Thus,this work provides a novel strategy of device structure optimization for significantly improving the photoresponsive characteristics of TFT photodetectors.
基金This work was financially supported by the National Key Research and Development Program of China(2022YFB3602902)the Key Projects of National Natural Science Foundation of China(62234004)+5 种基金Innovation and Entrepreneurship Team of Zhejiang Province(2021R01003)Science and Technology Innovation 2025 Major Project of Ningbo(2022Z085)Ningbo 3315 Programme(2020A-01-B)YONGJIANG Talent Introduction Programme(2021A-038-B)Flexible Electronics Zhejiang Province Key Laboratory Fund Project(2022FEO02)Zhejiang Provincial Natural Science Foundation of China(LR21F050001).
文摘CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.
基金supported by the National Natural Science Foundation of China(Nos.21736006 and 21978132)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Perovskite quantum dots(PQDs) possess remarkable optical properties, such as tunable photoluminescence(PL) emission spectra, narrow full width at half maximum(FWHM) and high PL quantum yield(QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen(FAPbX_(3), X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene(core) and polymethyl methacrylate(shell) coated FAPbCl_(3) QDs(abbreviated as PS/FAPbCl_(3)/PMMA, hereinafter), green-emissive PS/FAPbBr_(3)/PMMA and redemissive PS/FAPbI_(3)/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover,the PS/FAPbBr_(3)/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green-and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.
基金supported financially by the Ministry of Science and Technology of China(2017YFA0204502)the National Natural Science Foundation of China(NSFC)(22275104,21905145)+1 种基金the project ZR2021YQ06 supported by Shandong Provincial Natural Science FoundationScientific Research Foundation in Qilu University of Technology(Shandong Academy of Sciences)(2022PY013).
文摘Micro/nanoscale photonic barcodes hold great potential for broad applications in items tracking,mul-tiplexed bioassays and anti-counterfeiting.The ever-increasing demand in advanced anti-counterfeiting applications calls for micro/nanoscale barcodes with accurate recognition,large encoding capacity and high security level.Here,we proposed a strategy to construct the dual-stimuli responsive photonic barcodes based on the perovskite quantum dots(PQDs)doped polymer whispering-gallery-mode(WGM)microcavities via swelling-deswelling method.Benefiting from the well-defined spherical microcavities,the photoluminescence(PL)spectra of as-prepared composites exhibit a series of sharp peaks characteristics resulting from the effective WGM modulation,which constitutes the fingerprint of a specific resonator and thus allows a definition of photonic barcodes.On this basis,we achieved responsive photonic barcodes based on the volatile polar-solvent-controlled luminescence in the mi-crospheres benefitting from the space-confined microcavities and the ionic feature of the PQDs.More-over,the light-controlled photonic barcodes have further been acquired through reversibly regulating the inactivation and activation of the energy transfer(ET)process between the PQDs and photochromic dyes.The well-established protocols of PQDs@WGM enable the development of distinct responsive barcodes with multi-responsive features,which will pave an avenue to new types of flexible WGM-based components for optical data recording and security labels.
基金Ministry of Trade,Industry and Energy,Grant/Award Numbers:20017439,20021915National Research Foundation of Korea,Grant/Award Number:2019R1A2C1087653。
文摘Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel behavior,they have intrinsic stability issues.In this study,an effectively silane barrier-capped quantum dot(QD@APDEMS)is thinly applied onto a bulk perovskite photosensitive layer for use in photodetectors.QD@APDEMS is synthesized with a silane ligand with hydrophobic CH_(3)-terminal groups,resulting in excellent dispersibility and durability to enable effective coating.The introduction of the QD@APDEMS layer results in the formation of a lowdefect perovskite film with enlarged grains.This is attributed to the grain boundary interconnection effect via interaction between the functional groups of QD@APDEMS and uncoordinated Pb^(2+)in grain boundaries.By passivating the grain boundaries,where various trap sites are distributed,hole chargecarrier injection and shunt leakage can be suppressed.Also,from the energy point of view,the deep highest occupied molecular orbital(HOMO)level of QD@APDEMS can work as a hole charge injection barrier.Improved charge dynamics(generation,transfer,and recombination properties)and reduced trap density of QD@APDEMS are demonstrated.When this perovskite film is used in a photodetector,the device performance(especially the detectivity)stands out among existing perovskites evaluated for energy sensing device applications.
基金Project supported by the National Natural Science Foundation of China(U1904178.11704202.11504131,51374132)the Program for Science&Technology Innovation Talents in Universities of Henan Province(19HASTIT019).
文摘Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)PQDs has been recognized as one of the promising candidates.However,the low photoluminescence quantum yields(PLQYs)hinder its practical application in optoelectronic devices.Here,w e successfully prepared Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs with effective white light-emission by modified ligandassisted recrystallization method.The realization of white light-emission is attributed to the broadband blue emission of excitons and the red emission(^(4)G_(5/2)-^(6)HJ(J=5/2,7/2,9/2))of Sm^(3+)ions for Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs.More importantly,compared with the undoped Cs_(3)Bi_(2)Br_(g)PQDs,the PLQYs of Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs are improved from 10.9%to 20.8%,and the anti-water stability is also obviously improved.Finally,the Sm^(3+)ions doped PQDs based white light-emitting diodes(LEDs)with luminous efficiency of 12.6 lm/W were explored,which indicates that there is a potential prospect of lead-free PQDs in white light lighting application.
基金Project supported in part by National Natural Science Foundation of China(51402125)Natural Science Foundation of Shandong Province(ZR2020ME045,ZR2020ME046)。
文摘Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) quantum dots(QDs)mesoporous hollow nanocomposites with good luminescent properties and high stability were built.Among which,the hollow Gd_(2)O_(3):Eu^(3+)spheres and CsPbBr_(3) QDs were prepared by urea homogeneous precipitation and hot-injection method,respectively.Finally,the Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs shell-core compounds were constructed through mechanical stirring.The structure,morphology,stability and luminescent properties were studied by Fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry/thermogravity(DSC/TG),X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),photoluminescence excitation/photoluminescence(PLE/PL)and life decay tools.Compared to the original CsPbBr_(3) QDs,Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs display better photostability,thermal stability and current stability.The resulting Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs composite exhibits good yellow emission.The Gd_(2)O_(3):Eu^(3+)@CsPbBr_(3) QDs mixed silicone resin was directly coated on the blue LED chip,then the w-LED device with the color coordinate of(0.31,0.32)was successfully assembled.The Gd_(2) O_(3):Eu^(3+)@CsPbBr_(3) QDs compounds with excellent luminescent properties and stability are expected to be widely used in lighting and display areas.
文摘The stability of lead halide perovskite quantum dots (PQDs) was improved by embedding them in carboxybenzene microcrystals. The resulting needle-shaped mixed microcrystals preserved the strong photoluminescence of the PQDs. Compared with previously reported polystyrene-encapsulated PQDs, the carboxybenzene crystals were robust and protected the dots from moisture and photodegradation. The enhanced stability was attributed to the tight matrix of carboxybenzene microcrystals, which protected the PQDs from moisture. This versatile strategy protected various QDs, including all-inorganic PQDs and chalcogenide QDs (e.g., CdSe/ZnS QDs and CuInS/ZnS QDs). It provides a facile and versatile method of protecting PQDs and may enable applications in solid-state systems with high color quality requirements such as displays, lasers, and light emitting diodes.
基金supported by the National Natural Science Foundation of China(Grant No.:21974074)Ningbo Public Welfare Technology Plan Project of China(Grant Nos.:2021Z056,2022Z170,2022S011,and 202002N3112)+2 种基金Zhejiang Provincial Top Discipline of Biological Engineering(Level A)(Grant Nos.:CX2021051 and KF2021004)Zhejiang Province Public Welfare Technology Application Research Analysis Test Plan(Grant No.:LGC20B 050006)K.C.Wong Magna Fund in Ningbo University.
文摘In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor polyhedral oligomeric silsesquioxane-perovskite quantum dots(cDNA-POSSPQDs)were used as encoded probes and combined with dual-stirring-bar-assisted signal amplification for pathogen quantification.In this system,bar 1 was labeled with the S.T.and V.P.Apts,and then bar 2 was functionalized with cDNA-POSS-PQDs.When S.T.and V.P.were introduced,pathogen-Apt complexes would form and be released into the supernatant from bar 1.Under agitation,the two complexes reached bar 2 and subsequently reacted with cDNA-POSS-PQDs,which were immobilized on MXene.Then,the encoded probes would be detached from bar 2 to generate FL signals in the supernatant.Notably,the pathogens can resume their free state and initiate next cycle.They swim between the two bars,and the FL signals can be gradually enhanced to maximum after several cycles.The FL signals from released encoded probes can be used to detect the analytes.In particular,live pathogens can be distinguished from dead ones by using an assay.The detection limits and linear range for S.T.and V.P.were 30 and 10 CFU/mL and 10^(2) -10^(6) CFU/mL,respectively.Therefore,this assay has broad application potential for simultaneous on-site detection of various live pathogenic bacteria in water.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.51602028,61905026,and 11874091)Jilin Province Science and Technology Development Project(Nos.20200301065RQ and 20190701024GH)+1 种基金Chinese Academy of Sciences(No.CAS-KLAOT-KF201803)Changchun University of Science and Technology(No.XJJLG-2017-01).
文摘Although laser pumping using electron beam(EB)has high transient power output and easy modulation based on perovskite quantum dot(PQD)film,its lasing emitting direction is the same as the pumped EB's direction.Thus,realizing the conventional direct device structure through the film lasing mechanism is extremely difficult.Therefore,using the random lasing principle,herein,we proposed a corona modulation device structure based on PQDs random laser pumped using an EB.We discussed and stimulated the optimized designed method of the device in terms of parameters of the electronic optical device and the utilization ratio of output power and its modulation extinction ratio,respectively.According to the simulation results,this type of device structure can effectively satisfy the new random lasing mechanism in terms of high-speed and high-power modulation.
基金Basic Science Research Program and National Honor Scientist Program through the National Research Foundation of Korea(NRF)(Nos.2010-0020414,2018R1D1A1B07043676).T.F.acknowledges support from the Centre for Quantum Technologies,National University of Singapore.
文摘Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-P6rot cavity-forming nanowires.We demonstrate the direct observation of lasing from transverse electromagnetic(TEM)modes with a long coherence time-9.5ps in coupled CsPbBr_(3) quantum dots,which dispense with an external cavity resonator and show how the wavelength of the modes can be controlled via two independent tuning-mechanisms.Controlling the pump power allowed us tofine-tune the TEM mode structure to the emission wavelength,thus providing a degree of control over the properties of the lasing signal.The temperature-tuning provided an additional degree of control over the wavelength of the lasing peak,importantly,maintained a constant full width at half maximum(FWHM)over the entire tuning range without mode-hopping.
基金supported by the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060,61971216)+3 种基金the Key Research and Development Project of Jiangsu Province(BE2019603,BE2019761,BE2020768)Jiangsu Province Top Health Talents Project(LGY2019001)Shenzhen Fundamental Research Program(JCYJ20190813152616459)the project funded by China Postdoctoral Science Foundation(2020M681556,2021T140318)。
文摘Perovskite quantum dots(PQDs)are new class of optoelectronic materials,which have been widely studied for their extraordinary physical properties.Attempts to develop these materials are tending to make their fabrication much controllable and extend their values in different areas.Here,we present a novel strategy for one-step in situ synthesis of PQD-encapsulated barcode particles with the assistance of microfluidic technique.By changing the halide ratio in perovskite precursor solutions that emulsified in microfluidic devices,a series of PQDs with different colors have been successfully fabricated,which made them ideal materials as barcodes.Because of the stable encapsulation of ethyleneglycol dimethacrylate(EGDMA)resin,the PQD-encapsulated barcode particles were with no cytotoxicity and could be anti-quenched.It was demonstrated for the first time that the PQD-encapsutated barcode particles by microfluidics were valuable for multiplex biomolecular encoding and assays.These features indicate that the PQD-encapsutated barcode particles by microfluidics are ideal for many practical applications and have a broad prospect in biomedical field.
基金supported by the National Natural Science Foundation of China(Grant No.51872014)the Recruitment Program of Global Experts,Fundamental Research Funds for the Central Universities and the“111”project(B17002).
文摘Formamidinium lead triiodide(FAPbI_(3))perovskite quantum dots(PQDs)show great advantages in photovoltaic applications due to their ideal bandgap energy,high stability and solution processability.The anti-solvent used for the post-treatment of FAPbI_(3) PQD solid flms signifcantly afects the surface chemistry of the PQDs,and thus the vacancies caused by surface ligand removal inhibit the optoelectronic properties and stability of PQDs.Here,we study the efects of diferent anti-solvents with diferent polarities on FAPbI_(3) PQDs and select a series of organic molecules for surface passivation of PQDs.The results show that methyl acetate could efectively remove surface ligands from the PQD surface without destroying its crystal structure during the post-treatment.The benzamidine hydrochloride(PhFACl)applied as short ligands of PQDs during the post-treatment could fll the A-site and X-site vacancies of PQDs and thus improve the electronic coupling of PQDs.Finally,the PhFACl-based PQD solar cell(PQDSC)achieves a power conversion efciency of 6.4%,compared to that of 4.63%for the conventional PQDSC.This work provides a reference for insights into the surface passivation of PQDs and the improvement in device performance of PQDSCs.
基金This work was supported by the Technology Innovation Program(No.20011317)Development of an adhesive material capable of morphing more than 50%for flexible devices with a radius of curvature of 1 mm or less funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite quantum dots(PeQDs)as active layer.Typical ZnO thin film transistors did not show a photocurrent under visible light illumination.However,ZnO TFTs decorated with PeQDs exhibited enhanced photocurrent upon exposure to visible light.The device had a responsivity of 567 A/W(617 A/W),a high detectivity of 6.59×10^(13)Jones(1.85×10^(14)J)and a high sensitivity of 10^(7)(10^(8))under green(blue)light at a low drain voltage of 0.1 V.The high photo-responsivity and detectivity under green light resulted from the combination of short ligands in the QDs films and the high mobility of the spray coated ZnO films.Those results are relevant for the development of low cost and low energy consumption phototransistors working in the visible range.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.22090024,51521002 and 62074059)the Basic and Applied Basic Research Major Program of Guangdong Province(Grant No.2019B030302007).
文摘Perovskite quantum dots(PeQDs)are considered potential display materials due to their high color purity,high photoluminescence quantum yield(PLQY),low cost and easy film casting.In this work,a novel electroluminescence(EL)device consisting of the interface layer of long alkyl-based oleylammonium bromide(OAmBr),which passivates the surface defects of PeQDs and adjusts the carrier transport properties,was designed.The PLQY of the OAmBr/PeQD bilayer was significantly improved.A high-performance EL device with the structure of indium tin oxide/poly(3,4-ethylenedioxythiophene)polystyrene sulfonate/poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)/OAmBr/PeQDs/2,2′,2′′-(1,3,5-benzinetriyl)-tris(1-phenyl-1H benzimidazole)/LiF/Al was constructed using a spin-coating method.A peak external quantum efficiency(EQE)of 16.5%at the emission wavelength of 646 nm was obtained.Furthermore,an efficient matrix EL device was fabricated using an inkjet printing method.A high-quality PeQD matrix film was obtained by introducing small amounts of polybutene into the PeQDs to improve the printing process.The EQE reached 9.6%for the matrix device with 120 pixels per inch and the same device structure as that of the spin-coating one.