Wide bandgap perovskite solar cells(PSCs)have attracted significant attention because they can be applied to the top cells of tandem solar cells.However,high open-circuit voltage(V_(OC))deficit(>0.4 V)result from p...Wide bandgap perovskite solar cells(PSCs)have attracted significant attention because they can be applied to the top cells of tandem solar cells.However,high open-circuit voltage(V_(OC))deficit(>0.4 V)result from poor crystallization and high non-radiative recombination losses become a serious limitation in the pursuit of high performance.Here,the relevance between different Pbl_(2)proportions and performance parameters are revealed through analysis of surface morphology,residual stress,and photostability.The increase of Pbl_(2)proportion promotes crystal growth and reduces the work function of the perovskite film surface and promotes the energy level alignment with the carrier transport layer,which decreased the V_(OC)deficit.However,residual PbI_(2)exacerbated the stress level of perovskite film,and the resulting lattice disorder deteriorated the photostability of the device.Ultimately,after the synergistic passivation of residual PbI_(2)and PEAI,the V_(OC)achieves 1.266 V and V_(OC)deficit is less than 0.4 V,the record value in wide bandgap PSCs.展开更多
Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology...Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology of blend film,thereby improving charge mobility and reducing energy loss within the corresponding film.Notably,the PM6:BP4F-UU device exhibited a higher open-circuit voltage(V_(oc))of 0.878 V compared to the PM6:BP4F-HU device with a V_(oc)of 0.863 V.Further,a new wide bandgap SMA named BTP-TA was designed and synthesized as the third component to the PM6:BP4F-UU host binary devices,which showed an ideal complementary absorption spectrum in PM6:BP4F-UU system.In addition,BTP-TA can achieve efficient intermolecular energy transfer to BP4F-UU by fluorescence resonance energy transfer(FRET)pathway,due to the good overlap between the photoluminescence(PL)spectrum of BTP-TA and the absorption region of BP4F-UU.Consequently,ternary devices with 15wt%BTP-TA exhibits broader photon utilization,optimal blend morphology,and reduced charge recombination compared to the corresponding binary devices.Consequently,PM6:BP4F-UU:BTP-TA ternary device achieved an optimal power conversion efficiency(PCE)of 17.83%with simultaneously increased V_(oc)of 0.905 V,short-circuit current density(J_(sc))of 26.14 mA/cm^(2),and fill factor(FF)of 75.38%.展开更多
Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a ...Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a need to reduce their losses and improve their performance to reduce electric power consumption. Current power semiconductor devices, such as inverters, are made of silicon (Si), but the performance of these Si power devices is reaching its limit due to physical properties and energy bandgap. To address this issue, recent developments in wide bandgap (WBG) semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), offer the potential for a new generation of power semiconductor devices that can perform significantly better than silicon-based devices. In this research, a green synthesized copper-zinc-tin-sulfide (CZTS) nanoparticle is proposed as a new WBG semiconductor material that could be used for optical and electronic devices. Its synthesis, consisting of the production methods and materials used, is discussed. The characterization is also discussed, and further research is recommended in the later sections to enable the continual advancement of this technology.展开更多
Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-j...Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-junction or tandem solar cells,which are designed to beyond the Shockley-Queisser(S-Q)limit of single-junction solar cells.However,the poor long-term operational stability of WBG PSCs limits their further employment and hinders the marketization of multi-junction or tandem solar cells.In this review,recent progresses on improving environmental stability of mixed-halide WBG PSCs through different strategies,including compositional engineering,additive engineering,interface engineering,and other strategies,are summarized.Then,the outlook and potential direction are discussed and explored to promote the further development of WBG PSCs and their applications in multijunction or tandem solar cells.展开更多
Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bomba...Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bombardment. The blue phosphors in this study were activated in air at temperatures suitable for glass substrates, which have been used in a number of applications. The effects of rare earth ions and oxide hosts on the blue-light-emitting properties of phosphors are discussed. In addition, novel blue-light emission was observed in certain typical undoped wide bandgap oxides. The luminescence of the oxides depends on the growth and annealing conditions under different atmospheres, suggesting that it is associated with the presence of oxygen vacancies. Radiative processes related to oxygen vacancies were also presented.展开更多
The deposition of hydrogenated amorphous silicon carbide (a-SiC.H) films from a mixture of silane, acetylene and hydrogen gas using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) process is repo...The deposition of hydrogenated amorphous silicon carbide (a-SiC.H) films from a mixture of silane, acetylene and hydrogen gas using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) process is reported. The variation of the deposition and film characteristics such as the deposition rate- optical bandgap, photoluminescence and the infra-red (IR) absorption as a function of the hydrogen dilution is investigated. The deposition rate increases to a maximum value of ~25 nm/min at a moderate hydrogen diIution ratio of ~20 [hydrogenflow (sccm)/acetylene+silane flow (sccm)], and decreases in response to a further increase in the hydrogen dilution. There is no strong dependence of the optical bandgap on the hydrogen dilution within the dilution range investigated (10 to 60), and the optical bandgap calculated from the E04 method varied marginally from ~2.85 eV to ~3.17 eV. The room temperaturephotoluminescence (PL) peak energy and intensity shows a prominent shift to a maximum value of ~2.17 eV corresponding to maximum PL intensity at a moderate hydrogen diIution of ~30.The PL intensity shows a strong dependence on the hydrogen dilution variation. IR absorption results show that films deposited at higher hydrogen dilution have more Si-C bonding.展开更多
As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(~ 4.8 eV) and l...As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(~ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.展开更多
Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovski...Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.展开更多
Quaternary approach has been receiving more and more attention due to its effectiveness in improving solar cell performance, while synthesis/selection of the fourth component is yet a key issue. Herein, we report a ch...Quaternary approach has been receiving more and more attention due to its effectiveness in improving solar cell performance, while synthesis/selection of the fourth component is yet a key issue. Herein, we report a chlorinated phthalimide based donor polymer(namely Ph I-Cl) having an ultra-wide bandgap(2.10 e V) and a deep HOMO(-5.58 e V) level. Addition of Ph I-Cl as the third component of PM6:Y6 and the fourth of PM6:Y6:PC71BM increases both hole and electron mobilities and gives rise to more balanced charge carriers mobilities. Both the short-circuit current-density and fill-factor are increased and open-circuit voltage is well maintained, delivering 17.0% and 18.1% efficiencies, respectively. These results demonstrate that chlorination on the side thiophene of phthalimide-based donor polymer is a way to make deep HOMO and ultra-wide bandgap donor polymer guest used for highly efficient ternary and quaternary strategies.展开更多
Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired ...Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired large open-circuit voltage(VOC)loss due to light-induced phase segregation and severe non-radiative recombination loss.Herein,antimony potassium tartrate(APTA)is added to perovskite precursor as a multifunctional additive that not only coordinates with unbonded lead but also inhibits the migration of halogen in perovskite,which results in suppressed non-radiative recombination,inhibited phase segregation and better band energy alignment.Therefore,a APTA auxiliary WBG PSC with a champion photoelectric conversion efficiency of 20.35%and less hysteresis is presented.They maintain 80%of their initial efficiencies under 100 mW cm^(-2)white light illumination in nitrogen after 1,000 h.Furthermore,by combining a semi-transparent WBG perovskite front cell with a narrow-bandgap tin–lead PSC,a perovskite/perovskite four-terminal tandem solar cell with an efficiency over 26%is achieved.Our work provides a feasible approach for the fabrication of efficient tandem solar cells.展开更多
Wide-bandgap semiconductors exhibit much larger energybandgaps than traditional semiconductors such as silicon,rendering them very promising to be applied in the fields of electronics and optoelectronics.Prominent exa...Wide-bandgap semiconductors exhibit much larger energybandgaps than traditional semiconductors such as silicon,rendering them very promising to be applied in the fields of electronics and optoelectronics.Prominent examples of semiconductors include SiC,GaN,ZnO,and diamond,which exhibitdistinctive characteristics such as elevated mobility and thermalconductivity.These characteristics facilitate the operation of awide range of devices,including energy-efficient bipolar junctiontransistors(BJTs)and metal-oxide-semiconductor field-effecttransistors(MOSFETs),as well as high-frequency high-electronmobility transistors(HEMTs)and optoelectronic components suchas light-emitting diodes(LEDs)and lasers.These semiconductorsare used in building integrated circuits(ICs)to facilitate theoperation of power electronics,computer devices,RF systems,andother optoelectronic advancements.These breakthroughs includevarious applications such as imaging,optical communication,andsensing.Among them,the field of power electronics has witnessedtremendous progress in recent years with the development of widebandgap(WBG)semiconductor devices,which is capable ofswitching large currents and voltages rapidly with low losses.However,it has been proven challenging to integrate these deviceswith silicon complementary metal oxide semiconductor(CMOS)logic circuits required for complex control functions.The monolithic integration of silicon CMOS with WBG devices increases thecomplexity of fabricating monolithically integrated smart integrated circuits(ICs).This review article proposes implementingCMOS logic directly on the WBG platform as a solution.However,achieving the CMOS functionalities with the adoption of WBGmaterials still remains a significant hurdle.This article summarizesthe research progress in the fabrication of integrated circuitsadopting various WBG materials ranging from SiC to diamond,with the goal of building future smart power ICs.展开更多
Organic solar cells(OSCs)have attracted wide research interests in the past decades.In recent years,our group mainly focused on the new photovoltaic materials design and device engineering technologies for highly effi...Organic solar cells(OSCs)have attracted wide research interests in the past decades.In recent years,our group mainly focused on the new photovoltaic materials design and device engineering technologies for highly efficient OSCs.This account mainly summarizes our recent studies on the structural design of wide bandgap(WBG)polymers and their morphology control as well as applications in OSCs.Additionally,we introduce our work on binary and ternary blend devices and tandem solar cells containing these materials.展开更多
This review summarized the recent progress of highly efficient wide bandgap(WBG) donor polymers and their applications in non-fullerene polymer solar cells(NF-PSCs). A brief introduction of the background of WBG donor...This review summarized the recent progress of highly efficient wide bandgap(WBG) donor polymers and their applications in non-fullerene polymer solar cells(NF-PSCs). A brief introduction of the background of WBG donor polymer developments was given. Then the research progress of the reported WBG donor polymers by classification of D-type and DààA type molecular backbones was reviewed. The resulting structure-property correlations of the WBG donor polymers were also discussed to highlight the importance of chemical modifications, which have promoted the great progress of NF-PSC field. Finally,an outlook for future innovations of WBG donor polymers and their NF-PSCs was provided.展开更多
The new phenomena induced by femtosecond lasers lead to the new area of ultrafast science.It is a significantchallenge to explain the phenomena associated with complex non-equilibrium and non-linear processes.Although...The new phenomena induced by femtosecond lasers lead to the new area of ultrafast science.It is a significantchallenge to explain the phenomena associated with complex non-equilibrium and non-linear processes.Althoughthere is a growing body of experimental observation,a comprehensive model remains undeveloped.We reviewthe challenges in understanding the photon absorption stage mainly for the femtosecond ablation of wide bandgap materialsat the intensities of 10^(13)~10^(14) W/cm^2.Major opinions and challenges in ionization mechanisms are presentedby primarily considering multiphoton ionization and avalanche ionization.展开更多
Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ...Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability.Over the past several years,benefitting from the sustainable innovations in laser technology and the significant progress in materials technology,megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor devices.Here,we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode,including the mechanism,system architecture,critical technology,and experimental demonstration of the proposed high-power photonic microwave sources.The outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.展开更多
基金the supports from the National Natural Science Foundation of China(Nos.62264012,62164009)Inner Mongolia Higher Education Research Project(No.NJZZ22343)+1 种基金Inner Mongolia University Research Foundation for Advanced Talents in 2021(No.10000-21311201/005)the Inner Mongolia Autonomous Region for Advanced Talents in 2020(No.12000-12102628)。
文摘Wide bandgap perovskite solar cells(PSCs)have attracted significant attention because they can be applied to the top cells of tandem solar cells.However,high open-circuit voltage(V_(OC))deficit(>0.4 V)result from poor crystallization and high non-radiative recombination losses become a serious limitation in the pursuit of high performance.Here,the relevance between different Pbl_(2)proportions and performance parameters are revealed through analysis of surface morphology,residual stress,and photostability.The increase of Pbl_(2)proportion promotes crystal growth and reduces the work function of the perovskite film surface and promotes the energy level alignment with the carrier transport layer,which decreased the V_(OC)deficit.However,residual PbI_(2)exacerbated the stress level of perovskite film,and the resulting lattice disorder deteriorated the photostability of the device.Ultimately,after the synergistic passivation of residual PbI_(2)and PEAI,the V_(OC)achieves 1.266 V and V_(OC)deficit is less than 0.4 V,the record value in wide bandgap PSCs.
基金the National Natural Science Foundation of China(Nos.52125306 and 21875286)。
文摘Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology of blend film,thereby improving charge mobility and reducing energy loss within the corresponding film.Notably,the PM6:BP4F-UU device exhibited a higher open-circuit voltage(V_(oc))of 0.878 V compared to the PM6:BP4F-HU device with a V_(oc)of 0.863 V.Further,a new wide bandgap SMA named BTP-TA was designed and synthesized as the third component to the PM6:BP4F-UU host binary devices,which showed an ideal complementary absorption spectrum in PM6:BP4F-UU system.In addition,BTP-TA can achieve efficient intermolecular energy transfer to BP4F-UU by fluorescence resonance energy transfer(FRET)pathway,due to the good overlap between the photoluminescence(PL)spectrum of BTP-TA and the absorption region of BP4F-UU.Consequently,ternary devices with 15wt%BTP-TA exhibits broader photon utilization,optimal blend morphology,and reduced charge recombination compared to the corresponding binary devices.Consequently,PM6:BP4F-UU:BTP-TA ternary device achieved an optimal power conversion efficiency(PCE)of 17.83%with simultaneously increased V_(oc)of 0.905 V,short-circuit current density(J_(sc))of 26.14 mA/cm^(2),and fill factor(FF)of 75.38%.
文摘Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a need to reduce their losses and improve their performance to reduce electric power consumption. Current power semiconductor devices, such as inverters, are made of silicon (Si), but the performance of these Si power devices is reaching its limit due to physical properties and energy bandgap. To address this issue, recent developments in wide bandgap (WBG) semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), offer the potential for a new generation of power semiconductor devices that can perform significantly better than silicon-based devices. In this research, a green synthesized copper-zinc-tin-sulfide (CZTS) nanoparticle is proposed as a new WBG semiconductor material that could be used for optical and electronic devices. Its synthesis, consisting of the production methods and materials used, is discussed. The characterization is also discussed, and further research is recommended in the later sections to enable the continual advancement of this technology.
基金the National Natural Science Foundation of China(Grant Nos.51602149,61705102,61605073,61935017,91833304,and 91733302)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)+5 种基金the Projects of International Cooperation and Exchanges NSFC(51811530018)the Startup Research Foundation from Nanjing Tech University(3827401783,3983500196)the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially-Appointed Professor programthe“Six talent peaks”Project in Jiangsu Province,Chinafunding from the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germanys Excellence Strategy-EXC 2089/1-390776260(e-conversion)。
文摘Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-junction or tandem solar cells,which are designed to beyond the Shockley-Queisser(S-Q)limit of single-junction solar cells.However,the poor long-term operational stability of WBG PSCs limits their further employment and hinders the marketization of multi-junction or tandem solar cells.In this review,recent progresses on improving environmental stability of mixed-halide WBG PSCs through different strategies,including compositional engineering,additive engineering,interface engineering,and other strategies,are summarized.Then,the outlook and potential direction are discussed and explored to promote the further development of WBG PSCs and their applications in multijunction or tandem solar cells.
基金Project supported bythe National Natural Science Foundation of China (50472079)
文摘Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bombardment. The blue phosphors in this study were activated in air at temperatures suitable for glass substrates, which have been used in a number of applications. The effects of rare earth ions and oxide hosts on the blue-light-emitting properties of phosphors are discussed. In addition, novel blue-light emission was observed in certain typical undoped wide bandgap oxides. The luminescence of the oxides depends on the growth and annealing conditions under different atmospheres, suggesting that it is associated with the presence of oxygen vacancies. Radiative processes related to oxygen vacancies were also presented.
文摘The deposition of hydrogenated amorphous silicon carbide (a-SiC.H) films from a mixture of silane, acetylene and hydrogen gas using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) process is reported. The variation of the deposition and film characteristics such as the deposition rate- optical bandgap, photoluminescence and the infra-red (IR) absorption as a function of the hydrogen dilution is investigated. The deposition rate increases to a maximum value of ~25 nm/min at a moderate hydrogen diIution ratio of ~20 [hydrogenflow (sccm)/acetylene+silane flow (sccm)], and decreases in response to a further increase in the hydrogen dilution. There is no strong dependence of the optical bandgap on the hydrogen dilution within the dilution range investigated (10 to 60), and the optical bandgap calculated from the E04 method varied marginally from ~2.85 eV to ~3.17 eV. The room temperaturephotoluminescence (PL) peak energy and intensity shows a prominent shift to a maximum value of ~2.17 eV corresponding to maximum PL intensity at a moderate hydrogen diIution of ~30.The PL intensity shows a strong dependence on the hydrogen dilution variation. IR absorption results show that films deposited at higher hydrogen dilution have more Si-C bonding.
基金supported by the National Natural Science Foundation of China(Nos.61521064,61522408,61574169,6 1334007,61474136,61574166)the Ministry of Science andTechnology of China(Nos.2016YFA0201803,2016YFA0203800,2017YFB0405603)+2 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Nos.QYZDB-SSWJSC048,QYZDY-SSW-JSC001)the Beijing Municipal Science and Technology Project(No.Z171100002017011)the Opening Project of the Key Laboratory of Microelectronic Devices&Integration Technology,Institute of Microelectronics of Chinese Academy of Sciences
文摘As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(~ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.
基金supported by the National Research Foundation of Korea (NRF)the Ministry of Science,ICT (2022M3J1A1085285,2019R1A2C1084010,and 2022R1A2C2006532)the Korea Electric Power Corporation (R20XO02-1)。
文摘Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.
基金the financial support of the Department of Science and Technology of Inner Mongolia (No.2020GG0192)Grassland Talents (No. CYYC10031)+1 种基金Inner Mongolia Normal University (No. 112/1004031962)the financial support of Collaborative Innovation Center for Water Environment Security of Inner Mongolia Autonomous Region,China (No. XTCX003)。
文摘Quaternary approach has been receiving more and more attention due to its effectiveness in improving solar cell performance, while synthesis/selection of the fourth component is yet a key issue. Herein, we report a chlorinated phthalimide based donor polymer(namely Ph I-Cl) having an ultra-wide bandgap(2.10 e V) and a deep HOMO(-5.58 e V) level. Addition of Ph I-Cl as the third component of PM6:Y6 and the fourth of PM6:Y6:PC71BM increases both hole and electron mobilities and gives rise to more balanced charge carriers mobilities. Both the short-circuit current-density and fill-factor are increased and open-circuit voltage is well maintained, delivering 17.0% and 18.1% efficiencies, respectively. These results demonstrate that chlorination on the side thiophene of phthalimide-based donor polymer is a way to make deep HOMO and ultra-wide bandgap donor polymer guest used for highly efficient ternary and quaternary strategies.
基金supported by the National High Technology Research and Development Program(2015AA050601)the National Natural Science Foundation of China(61904126,12134010,12174290)。
文摘Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired large open-circuit voltage(VOC)loss due to light-induced phase segregation and severe non-radiative recombination loss.Herein,antimony potassium tartrate(APTA)is added to perovskite precursor as a multifunctional additive that not only coordinates with unbonded lead but also inhibits the migration of halogen in perovskite,which results in suppressed non-radiative recombination,inhibited phase segregation and better band energy alignment.Therefore,a APTA auxiliary WBG PSC with a champion photoelectric conversion efficiency of 20.35%and less hysteresis is presented.They maintain 80%of their initial efficiencies under 100 mW cm^(-2)white light illumination in nitrogen after 1,000 h.Furthermore,by combining a semi-transparent WBG perovskite front cell with a narrow-bandgap tin–lead PSC,a perovskite/perovskite four-terminal tandem solar cell with an efficiency over 26%is achieved.Our work provides a feasible approach for the fabrication of efficient tandem solar cells.
基金supported by KAUST BaselineFund:BAS/1/1664-01-01,KAUST Near-term Grand Challenge Fund:REI/1/4999-01-01,KAUST Impact Acceleration Fund:REI/1/5124-01-01.
文摘Wide-bandgap semiconductors exhibit much larger energybandgaps than traditional semiconductors such as silicon,rendering them very promising to be applied in the fields of electronics and optoelectronics.Prominent examples of semiconductors include SiC,GaN,ZnO,and diamond,which exhibitdistinctive characteristics such as elevated mobility and thermalconductivity.These characteristics facilitate the operation of awide range of devices,including energy-efficient bipolar junctiontransistors(BJTs)and metal-oxide-semiconductor field-effecttransistors(MOSFETs),as well as high-frequency high-electronmobility transistors(HEMTs)and optoelectronic components suchas light-emitting diodes(LEDs)and lasers.These semiconductorsare used in building integrated circuits(ICs)to facilitate theoperation of power electronics,computer devices,RF systems,andother optoelectronic advancements.These breakthroughs includevarious applications such as imaging,optical communication,andsensing.Among them,the field of power electronics has witnessedtremendous progress in recent years with the development of widebandgap(WBG)semiconductor devices,which is capable ofswitching large currents and voltages rapidly with low losses.However,it has been proven challenging to integrate these deviceswith silicon complementary metal oxide semiconductor(CMOS)logic circuits required for complex control functions.The monolithic integration of silicon CMOS with WBG devices increases thecomplexity of fabricating monolithically integrated smart integrated circuits(ICs).This review article proposes implementingCMOS logic directly on the WBG platform as a solution.However,achieving the CMOS functionalities with the adoption of WBGmaterials still remains a significant hurdle.This article summarizesthe research progress in the fabrication of integrated circuitsadopting various WBG materials ranging from SiC to diamond,with the goal of building future smart power ICs.
基金This work was supported by the NSFC(21825502,22075190,21905185)the Foundation of State Key Laboratory of Polymer Materials Engineering(sklpme 2017-2-04)the Fundamental Research Funds for the Central Universities.
文摘Organic solar cells(OSCs)have attracted wide research interests in the past decades.In recent years,our group mainly focused on the new photovoltaic materials design and device engineering technologies for highly efficient OSCs.This account mainly summarizes our recent studies on the structural design of wide bandgap(WBG)polymers and their morphology control as well as applications in OSCs.Additionally,we introduce our work on binary and ternary blend devices and tandem solar cells containing these materials.
基金supported by the National Natural Science Foundation of China (Nos. 21825502, 51573107, 91633301 and 21432005)the Foundation of State Key Laboratory of Polymer Materials Engineering of China (No. sklpme2017-2-04)
文摘This review summarized the recent progress of highly efficient wide bandgap(WBG) donor polymers and their applications in non-fullerene polymer solar cells(NF-PSCs). A brief introduction of the background of WBG donor polymer developments was given. Then the research progress of the reported WBG donor polymers by classification of D-type and DààA type molecular backbones was reviewed. The resulting structure-property correlations of the WBG donor polymers were also discussed to highlight the importance of chemical modifications, which have promoted the great progress of NF-PSC field. Finally,an outlook for future innovations of WBG donor polymers and their NF-PSCs was provided.
基金supported by the National Natural Science Foundation of China(50705009)the 111 project China(B08043)+3 种基金the National“863”project of China(2008AA03Z301)the Changjiang Scholar Program of Chinathe Air Force Research Laboratory USA(FA8650-04-C-5704)the National Science Foundation USA(0423233)
文摘The new phenomena induced by femtosecond lasers lead to the new area of ultrafast science.It is a significantchallenge to explain the phenomena associated with complex non-equilibrium and non-linear processes.Althoughthere is a growing body of experimental observation,a comprehensive model remains undeveloped.We reviewthe challenges in understanding the photon absorption stage mainly for the femtosecond ablation of wide bandgap materialsat the intensities of 10^(13)~10^(14) W/cm^2.Major opinions and challenges in ionization mechanisms are presentedby primarily considering multiphoton ionization and avalanche ionization.
基金supported in part by the National Natural Science Foundation of China(Nos.62071477 and 62101577)the Natural Science Foundation of Hunan Province(No.2021JJ40660)。
文摘Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability.Over the past several years,benefitting from the sustainable innovations in laser technology and the significant progress in materials technology,megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor devices.Here,we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode,including the mechanism,system architecture,critical technology,and experimental demonstration of the proposed high-power photonic microwave sources.The outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.