An organic visible-photocatalytic-adsorbence mechanism to high-efficient removal of heavy metal antimony ions

Purification of emerging heavy metal antimony contaminated water based on advanced ingenious strategies.An activated modified coconut shell charcoal(CSC)was synthesized and evaluated as a substrate-supported loaded organic photovoltaic material,PM6:PYIT:PM6-b-PYIT,to prepare a surprisingly highly efficient,stable,environmentally friendly,and recyclable organic photocatalyst(CSC–N–P.P.P),which showed excellent effects on the simultaneous removal of Sb(Ⅲ)and Sb(Ⅴ).The removal efficiency of CSC-N-P.P.P on Sb(Ⅲ)and Sb(Ⅴ)reached an amazing 99.9%in quite a short duration of 15 min.At the same time,under ppb level and indoor visible light(~1 W m^(2)),it can be treated to meet the drinking water standards set by the European Union and the U.S.National Environmental Protection Agency in 5 min,and even after 25 cycles of recycling,the efficiency is still maintained at about 80%,in addition to the removal of As(Ⅲ),Cd(Ⅱ),Cr(Ⅵ),and Pb(Ⅱ)can also be realized.The catalyst not only solves the problems of low reuse rate,difficult structure adjustment and high energy consumption of traditional photocatalysts but also has strong applicability and practical significance.The pioneering approach provides a much-needed solution strategy for removing highly toxic heavy metal antimony pollution from the environment.

Sol-gel-based porous Ti-doped tungsten oxide films for high-performance dual-band electrochromic smart windows

Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current strategy for building DESWs is to screen materials for composite or prepare plasmonic nanocrystal films.These rigorous preparation processes seriously limit the further development of DESWs.Herein,we report a facile and effective sol-gel strategy using a foaming agent to achieve porous Ti-doped tungsten oxide film for the high performance of DESWs.The introduction of foaming agent polyvinylpyrrolidone during the film preparation can increase the specific surface area and free carrier concentration of the films and enhance their independent regulation ability of near-infrared electrochromism.As a result,the optimal film shows excellent dual-band electrochromic properties,including high optical modulation(84.9%at 633 nm and 90.3%at 1200 nm),high coloration efficiency(114.9 cm^(2) C^(-1) at 633 nm and 420.3 cm^(2) C^(-1) at 1200 nm),quick switching time,excellent bistability,and good cycle stability(the transmittance modulation losses at 633 and 1200 nm were 11%and 3.5%respectively after 1000 cycles).A demonstrated DESW fabricated by the sol-gel film showed effective management of heat and light of sunlight.This study represents a significant advance in the preparation of dual-band electrochromic films,which will shed new light on advancing electrochromic technology for future energy-saving smart buildings.

A High-Performance Solid-State Na–CO_(2)Battery with Poly(Vinylidene Fluoride-co-Hexafluoropropylene)−Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)Electrolyte

The recovery and utilization of carbon dioxide(CO_(2))is the key to achieve the targets of peak carbon dioxide emissions and carbon neutrality.The Na-CO_(2)battery made with cheap alkali metal sodium and greenhouse gas CO_(2)is an effective strategy to consume CO_(2)and store clean renewable energy.However,the liquid electrolyte volatilization in the open battery system and inevitable dendrite growth restrict the application of Na-CO_(2)batteries.In this work,magnesium-doped Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)was studied as a solid electrolyte for solid-state Na-CO_(2)batteries.The ionic conductivity of Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)reaches 1.16 mS cm^(−1)at room temperature by replacing Zr ions in Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)with Mg ions,and the structural changes are analyzed by neutron powder diffraction.The composite electrolyte consisting of highly conductive Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)and high processability poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)is utilized for the first time to assemble a solid-state Na-CO_(2)battery.The cell shows a full discharge capacity of 7720 mAh g^(−1)at 200 mA g^(−1).The middle gap voltage is lower than 2 V after 120 cycles at 200 mA g^(−1)and at a cut-off capacity of 500 mAh g^(−1).This work demonstrates a promising strategy to design high-performance solid-state Na-CO_(2)batteries.

Reversible Zn^(2+) Insertion in Tungsten Ion-Activated Titanium Dioxide Nanocrystals for Electrochromic Windows

Zinc-anode-based electrochromic devices(ZECDs) are emerging as the next-generation energy-e cient transparent electronics. We report anatase W-doped TiO_(2) nanocrystals(NCs) as a Zn^(2+) active electrochromic material. It demonstrates that the W doping in TiO_(2) highly reduces the Zn^(2+) intercalation energy,thus triggering the electrochromism. The prototype ZECDs based on W-doped TiO_(2) NCs deliver a high optical modulation(66% at 550 nm),fast spectral response times(9/2.7 s at 550 nm for coloration/bleaching),and good electrochemical stability(8.2% optical modulation loss after 1000 cycles).

Advances and Challenges in Two‑Dimensional Organic–Inorganic Hybrid Perovskites Toward High‑Performance Light‑Emitting Diodes

Two-dimensional(2D)perovskites are known as one of the most promising luminescent materials due to their structural diversity and outstanding optoelectronic properties.Compared with 3D perovskites,2D perovskites have natural quantum well structures,large exciton binding energy(Eb)and outstanding thermal stability,which shows great potential in the next-generation displays and solidstate lighting.In this review,the fundamental structure,photophysical and electrical properties of 2D perovskite films were illustrated systematically.Based on the advantages of 2D perovskites,such as special energy funnel process,ultrafast energy transfer,dense film and low efficiency roll-off,the remarkable achievements of 2D perovskite light-emitting diodes(PeLEDs)are summarized,and exciting challenges of 2D perovskite are also discussed.An outlook on further improving the efficiency of pure-blue PeLEDs,enhancing the operational stability of PeLEDs and reducing the toxicity to push this field forward was also provided.This review provides an overview of the recent developments of 2D perovskite materials and LED applications,and outlining challenges for achieving the high-performance devices.

Recent progress of infrared photodetectors based on lead chalcogenide colloidal quantum dots

Commercial photodetectors based on silicon are extensively applied in numerous fields. Except for their high performance, their maximum absorption wavelength is not over than 1100 nm and incident light with longer wavelengths cannot be detected; in addition, their cost is high and their manufacturing process is complex. Therefore, it is meaningful and significant to extend absorption wavelength, to decrease cost, and to simplify the manufacturing process while maintaining high performance for photodetectors. Due to the properties of size-dependent bandgap tunability, low cost, facile processing,and substrate compatibility, solution–processed colloidal quantum dots(CQDs) have recently gained significant attention and become one of the most competitive and promising candidates for optoelectronic devices. Among these CQDs, lead chalcogenide CQDs are getting very prominent and are widely investigated. In this paper, the recent progress of infrared(IR) photodetectors based on lead sulfide(PbS), lead selenide(PbSe), and ternary PbS_x Se_(1-x) CQDs, and their underlying concepts, breakthroughs, and remaining challenges are reviewed, thus providing guidance for designing high-performance quantum-dot IR photodetectors.

Enhancing the photo-luminescence stability of CH_(3)NH_(3)PbI_(3) film with ionic liquids

The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However,it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI_(3) perovskite film on the glass substrate with/without the ionic liquid(IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_(4)) by a simple two-step sequential solution method. The additive of BMIMBF_(4)can improve the quality of crystal structure. Moreover, the photo-luminescence(PL) intensity of MAPbI_(3) film with BMIMBF_(4) is much stronger than the pure MAPbI_(3) film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave(CW) laser, the fluorescent duration of the MAPbI_(3) film with BMIMBF_(4) is approximately 2.75 min, while the pure MAPbI;film is only about 6 s. In fact, ionic liquid of BMIMBF_(4) in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI_(3) into CH_(3)NH_(3)and PbI_(2) and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF;possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.

Temperature-dependent self-trapped exciton emission in Cu(I) doped zinc-based metal halides from well-resolved excited state structures

Zero-dimensional metal halides are of unique structures and tunable photoluminescence properties,showing great potential applications such as light-emitting diodes(LEDs)and sensing.Herein,we successfully synthesized Cu^(+)doped(MA)_(2)ZnCl_(4)metal halides by a slow evaporation solvent method.The introduction of Cu^(+)results in sky-blue self-trapped exciton emission in(MA)_(2)ZnCl_(4) at 486 nm at room temperature,and a photoluminescence quantum yield is as high as 54.9%.Interestingly,at low temperatures,Cu^(+)-doped(MA)_(2)ZnCl_(4) exhibits two emission peaks located at 482 and 605 nm,respectively.This temperaturedependent dual emission indicates two excited state structures that exist on the triplet excited-state potential energy surface.In addition,the temperature sensor we fitted has good performance(Sr=1.65%·K^(−1)),which is the first attempt in Cu^(+) doped Znbased metal halides.Our work enriches the family of sky-blue metal halides and provides a promising strategy for building skyblue LEDs.

A ratiometric optical thermometer with dual-color emission based on Eu^(2+)-doped CsCu_(2)I_(3) microcrystals

With the increasing demand for non-co ntact fluorescence intensity ratio-based optical thermometry,novel phosphor materials with high-efficiency,dual-emitting centers,and differentiable temperature sensitivity are highly desired,In this wo rk,rare earth Eu^(2+) ions were incorporated Wnto CsCu_(2)I_(3) microcrystals by solidstate reaction,Under a single UV excitation,the as-synthesized samples exhibit two emissions:452 nm blue emission from the 5d→4f transition of Eu^(2+)and 582 nm yellow emission from self-trapped exciton e mission of CsCu_(2)I_(3).The photoluminescence quantum yield reaches to 50%,The dual-band emission of Eu^(2+)-doped CsCu_(2)I_(3) shows different temperature responses in the range of 260-360 K.Based on fluorescence intensity ratio technology,the maximum absolute sensitivity and re Iative sensitivity are 0.091 K^(-1)(at 360 K) and 2.60%/K(at 260 K),respectively.These results suggest that Eu^(2+)-doped GsCu_(2)I_(3) could be a good candidate for highly sensitive optical thermometer.

Realizing efficient emission and triple-mode photoluminescence switching in air-stable tin(IV)-based metal halides via antimony doping and rational structural modulation

Recently,many lead-free metal halides with diverse structures and highly efficient emission have been reported.However,their poor stability and single-mode emission color severely limit their applications.Herein,three homologous Sb^(3+)-doped zero-dimensional(0D)air-stable Sn(IV)-based metal halides with different crystal structures were developed by inserting a single organic ligand into SnCl_(4)lattice,which brings different optical properties.Under photoexcitation,(C_(25)H_(22)P)SnC_(l5)@Sb⋅CH_(4O)(Sb^(3+)−1)does not emit light,(C_(25)H_(22)P)_(2)SnC_(l6)@Sb-α(Sb^(3+)−2α)shines bright yellow emission with a photoluminescence quantum yield(PLQY)of 92%,and(C_(25)H_(22)P)_(2)SnC_(l6)@Sb-β(Sb^(3+)−2β)exhibits intense red emission with a PLQY of 78%.The above three compounds show quite different optical properties should be due to their different crystal structures and the lattice distortions.Particularly,Sb^(3+)−1 can be successfully converted into Sb^(3+)−2αunder the treatment of C_(25)H_(22)PCl solution,accompanied by a transition from nonemission to efficient yellow emission,serving as a“turn-on”photoluminescence(PL)switching.Parallelly,a reversible structure conversion between Sb^(3+)−2αand Sb^(3+)−2βwas witnessed after dichloromethane or volatilization treatment,accompanied by yellow and red emission switching.Thereby,a triple-mode tunable PL switching of off-onI-onII can be constructed in Sb^(3+)-doped Sn(IV)-based compounds.Finally,we demonstrated the as-synthesized compounds in fluorescent anticounterfeiting,information encryption,and optical logic gates.

A Two-in-One Annealing Enables Dopant Free Block Copolymer Based Organic Solar Cells with over 16% Efficiency

The organic solar cells(OSCs)based on block copolymer systems bear the hope of achieving the optimal balance of power conversion efficiency(PCE)and stability,but the key index,PCE of this type devices is still low.To improve the efficiency,regulating the thin-film morphology is always the core engineering,which is usually achieved via two aspects:precursor optimization and post treatments.

Origin of singlet self-trapped exciton and enhancement of photoluminescence quantum yield of organic–inorganic hybrid antimony(III)chlorides with the[SbCl_(5)]^(2)−units

Sb-based organic–inorganic hybrid metal halides(OIHMHs)with[SbCl5]2−units have been widely reported due to high photoluminescence quantum yield(PLQY)and occasional multiple self-trapped exciton(STE)emission bands mainly out of singlet and triplet states,and their multi-band emission is important in white light-emitting diode(WLED).However,not all these OIHMH compounds can produce both emissions out of singlet STE and triplet STE at room temperature simultaneously.It is crucial to consider how the singlet STE generates and retains to emit light at room temperature for this material’s design and application.Herein,a strategy is proposed that can significantly lift Sb halide PLQY by synthesizing two Sb-based OIHMHs using organic amine cations of different-sized and-quantity,which modulate the distance of neighboring emission centers.Therein,the occurrence of singlet STE emission is found to be closely related to the distance of[SbCl_(5)]^(2)−units and local unit distortion in the lattice.The larger distance can produce smaller local distortions,favoring the formation of the singlet STE emission band at higher energy.This is the first work to reveal the relationship between the local structure and the origin of the singlet STE emission band,providing new insights into the modulation of the Sb-based OIHMH’s emission.

Multifunctional all-polymer photovoltaic blend with simultaneously improved efficiency(18.04%),stability and mechanical durability

One of the most appealing material systems for solar energy conversion is allpolymer blend.Presently,the three key merits(power conversion efficiency,operation stability and mechanical robustness)exhibited a trade-off in a particular all-polymer blend system,which greatly limit its commercial application.Diverting the classic ternary tactic of organic solar cells based on polymer,nonfullerene small molecule and fullerene,herein we demonstrate that the three merits of a benchmark all-polymer blend PM6:PY-IT can be simultaneously maximized via the introduction of a polymerized fullerene derivative PPCBMB.Importantly,the addition of the guest component promoted the power conversion efficiency of PM6:PY-IT blend from 16.59%to 18.04%.Meanwhile,the device stability and film ductility are also improved due to the addition of this polymerized fullerene material.Morphology and device physics analyses reveal that optimal ternary system contains well-maintained molecular packing and crystallinity,being beneficial to keeping favorable charge transport and the reduced domain size contributed to charge generation and ductility improvement.Furthermore,the ternary photovoltaic blend was successfully used as photocatalysts,and an excellent heavy metal removal from water was demonstrated.This study showcases the multi-functions of all-polymer blends via the use of polymerized fullerenes.

A Two-in-One Annealing Enables Dopant Free Block Copolymer Based Organic Solar Cells with over 16%Efficiency

The caption of Figure 4:“Figure 4(a)2D-GIWAXS patterns.(b)IP and(c)OOP line cuts.Calculated results of d-spacing and CL values for(d)IP and(e)OOP directions.”should be corrected to“Figure 4(a)Jph vs Veff relationships.(b)VOC and(c)JSC vs light intensity plots.Hole-only(d)and electron-only(e)device results.(f)Summarizedμh,μe and ratios.”

Broadband perovskite quantum dot spectrometer beyond human visual resolution

The quantum dot spectrometer,fabricated by integrating different quantum dots with an image sensor to reconstruct the target spectrum from spectral-coupled measurements,is an emerging and promising hyperspectrometry technology with high resolution and a compact size.The spectral resolution and spectral range of quantum dot spectrometers have been limited by the spectral variety of the available quantum dots and the robustness of algorithmic reconstruction.Moreover,the spectrometer integration of quantum dots also suffers from inherent photoluminescence emission and poor batch-to-batch repeatability.In this work,we developed nonemissive in situ fabricated MA_(3)Bi_(2)X_(9) and Cs_(2)SnX_(6)(MA=CH_(3)NH_(3);X=Cl,Br,I)perovskite-quantum-dot-embedded films(PQDFs)with precisely tunable transmittance spectra for quantum dot spectrometer applications.The resulting PQDFs contain in situ fabricated perovskite nanocrystals with homogenous dispersion in a polymeric matrix,giving them advantageous features such as high transmittance efficiency and good batch-to-batch repeatability.By integrating a filter array of 361 kinds of PQDFs with a silicon-based photodetector array,we successfully demonstrated the construction of a perovskite quantum dot spectrometer combined with a compressive-sensing-based total-variation optimization algorithm.A spectral resolution of ~1.6 nm was achieved in the broadband of 250-1000 nm.The performance of the perovskite quantum dot spectrometer is well beyond that of human eyes in terms of both the spectral range and spectral resolution.This advancement will not only pave the way for using quantum dot spectrometers for practical applications but also significantly impact the development of artificial intelligence products,clinical treatment equipment,scientific instruments,etc.

Boosting triplet self-trapped exciton emission in Te(IV)-doped Cs_(2)SnCl_(6) perovskite variants

Perovskite variants have attracted wide interest because of the lead-free nature and strong self-trapped exciton (STE) emission. Divalent Sn(II) in CsSnX3 perovskites is easily oxidized to tetravalent Sn(IV), and the resulted Cs2SnCl6 vacancy-ordered perovskite variant exhibits poor photoluminescence property although it has a direct band gap. Controllable doping is an effective strategy to regulate the optical properties of Cs2SnX6. Herein, combining the first principles calculation and spectral analysis, we attempted to understand the luminescence mechanism of Te4+-doped Cs2SnCl6 lead-free perovskite variants. The chemical potential and defect formation energy are calculated to confirm theoretically the feasible substitutability of tetravalent Te4+ ions in Cs2SnCl6 lattices for the Sn-site. Through analysis of the absorption, emission/excitation, and time-resolved photoluminescence (PL) spectroscopy, the intense green-yellow emission in Te4+:Cs2SnCl6 was considered to originate from the triplet Te(IV) ion 3P1→1S0 STE recombination. Temperature-dependent PL spectra demonstrated the strong electron-phonon coupling that inducing an evident lattice distortion to produce STEs. We further calculated the electronic band structure and molecular orbital levels to reveal the underlying photophysical process. These results will shed light on the doping modulated luminescence properties in stable lead-free Cs2MX6 vacancy-ordered perovskite variants and be helpful to understand the optical properties and physical processes of doped perovskite variants.

Highly luminescent and stable lead-free cesium copper halide perovskite powders for UV-pumped phosphor-converted light-emitting diodes

Lead halide perovskites have drawn extensive attention over recent decades owing to their outstanding photo-electric performances.However,their toxicity and instability are big issues that need to be solved for further commercialization.Herein,we adopt a facile dry ball milling method to synthesize lead-free Cs3Cu2X5(X=I,CI)perovskites with photoluminescence(PL)quantum yield up to 60%.The optical features including broad emission spectrum,large Stokes shift,and long PL lifetime can be attributed to self-trapped exciton recombination.The as-synthesized blue emissive Cs3Cu2I5 and green emissive Cs3Cu2Cl5 lead-free perovskite powders have good thermal stability and photostability.Furthermore,UV-pumped phosphor-converted light-emitting diodes were obtained by using Cs3Cu2I5 and Cs3Cu2Cl5 as phosphors.

Solution-processed,flexible and broadband photodetector based on CsPbBr_(3)/PbSe quantum dot heterostructures

Due to their promising applications in foldable displays,optical communication equipment and environmental monitoring systems,flexible and broadband optoelectronic devices have gained extensive attention in recent years.Here,a flexible and broadband photodetector based on CsPbBr_(3)/PbSe quantum dot(QD) heterostructures is firstly presented.The integrated QD heterostructures possess consecutive detection range from ultraviolet(UV) to long-wave length infrared(LW-IR) regions with efficient light absorption and chemical stability,in comparison with the pristine PbSe QDs.Systematic material characterizations reveal the improved exciton dissociation,carrier transport and carrier lifetime of the QD heterostructures.Flexible photodetector Ag/CsPbBr_(3)/PbSe/Ag demonstrate a high responsivity of 7.17 A/W with a specific detectivity of 8.97 × 10^(12) Jones under 25 μW/cm^(2) 365 nm illumination at 5 V.Furthermore,it could maintain 91.2 %(or 94.9 %) of its initial performance even after bending for thousands of times(or exposing in ambient air for 4 weeks).More importantly,its re s ponse time is shortened more than three orders of magnitude as that of pristine PbSe QDs-based photodetectors.Therefore,it provides a feasible and promising method for the next-generation high-performance broadband photodetectors via constructing heterostructures of various QDs.

Highly efficient green InP-based quantum dot light-emitting diodes regulated by inner alloyed shell component

InP-based quantum dot light-emitting diodes(QLEDs),as less toxic than Cd-free and Pb-free optoelectronic devices,have become the most promising benign alternatives for the next generation lighting and display.However,the development of green-emitting InP-based QLEDs still remains a great challenge to the environmental preparation of InP quantum dots(QDs)and superior device performance.Herein,we reported the highly efficient green-emitting InP-based QLEDs regulated by the inner alloyed shell components.Based on the environmental phosphorus tris(dimethylamino)phosphine((DMA)3P),we obtained highly efficient InP-based QDs with the narrowest full width at half maximum(~35 nm)and highest quantum yield(~97%)by inserting the gradient inner shell layer ZnSe_(x)S_(1-x)without further post-treatment.More importantly,we concretely discussed the effect and physical mechanism of ZnSe_(x)S_(1-x)layer on the performance of QDs and QLEDs through the characterization of structure,luminescence,femtosecond transient absorption,and ultraviolet photoelectron spectroscopy.We demonstrated that the insert inner alloyed shell ZnSe_(x)S_(1-x)provided bifunctionality,which diminished the interface defects upon balancing the lattice mismatch and tailored the energy levels of InP-based QDs which could promote the balanced carrier injection.The resulting QLEDs applying the InP/ZnSe_(0.7)S_(0.3)/ZnS QDs as an emitter layer exhibited a maximum external quantum efficiency of 15.2%with the electroluminescence peak of 532 nm,which was almost the highest record of InP-based pure green-emitting QLEDs.These results demonstrated the applicability and processability of inner shell component engineering in the preparation of high-quallity InP-based QLEDs.

Interfacial polaron in quantum dots and luminescent porous silicon

Polaronic effect is important in the current researches on quantum dots (QD). This paper reported a new concept of the 'confined polaron', their size dependent formation possibilities and energy variation in different QD systems, with an indication of contribution from both intrinsic and/or extrinsic phonons. To understand the spectro-scopic characteristics of porous silicon (PS), we find that luminescence behavior of oxidized porous silicon is in good agreement with the model of interfacial confined polaron in QDs. This conclusion is useful to unveiling the mechanmism of PS luminescence.