Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of ...Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP PSCs.Inspired by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer counterparts.Herein,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are realized.These films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared film.Accordingly,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to date.Importantly,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.展开更多
The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovs...The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovskites with low bandgaps have been rapidly developed,and their single junction solar cells have reached power conversion efficiency(PCE)over 21%,which also makes them ideal candidate as low bandgap sub-cell for tandem device.Nevertheless,due to the incorporation of unstable Sn^(2+),the stability issue becomes the vital problem for the further development of Sn-Pb mixed perovskite solar cells(PSCs).In this review,we are dedicated to give a full view in current understanding on the stability issue of SnPb mixed perovskites and their PSCs.We begin with the demonstration on the origin of instability of Sn-Pb mixed perovskites,including oxidation of Sn^(2+),defects,and interfacial layer induced instability.Sequentially,the up-to-date developments on the stability improvement of Sn-Pb mixed perovskites and their PSCs is systematically reviewed,including composition engineering,additive engineering,and interfacial engineering.At last,the current challenges and future perspectives on the stability study of Sn-Pb mixed PSCs are discussed,which we hope could promote the further application of Sn-Pb mixed perovskites towards commercialization.展开更多
Thin-film flexible solar cells are lightweight and mechanically robust.Along with rapidly advancing battery technology,flexible solar panels are expected to create niche products that require lightweight,mechanical fl...Thin-film flexible solar cells are lightweight and mechanically robust.Along with rapidly advancing battery technology,flexible solar panels are expected to create niche products that require lightweight,mechanical flexibility,and moldability into complex shapes,such as roof-panel for electric automobiles,foldable umbrellas,camping tents,etc.In this paper,we provide a comprehensive assessment of relevant materials suitable for making flexible solar cells.Substrate materials reviewed include metals,ceramics,glasses,and plastics.For active materials,we focus primarily on emerging new semiconductors including small organic donor/acceptor molecules,conjugated donor/acceptor polymers,and organometal halide perovskites.For electrode materials,transparent conducting oxides,thin metal films/nanowires,nanocarbons,and conducting polymers are reviewed.We also discuss the merits,weaknesses,and future perspectives of these materials for developing next-generation flexible photovoltaics.展开更多
Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial cont...Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.展开更多
The advancement of contemporary X-ray imaging heavily depends on discovering scintillators that possess high sensitivity,robust stability,low toxicity,and a uniform size distribution.Despite significant progress in th...The advancement of contemporary X-ray imaging heavily depends on discovering scintillators that possess high sensitivity,robust stability,low toxicity,and a uniform size distribution.Despite significant progress in this field,the discovery of a material that satisfies all of these criteria remains a challenge.In this study,we report the synthesis of monodisperse copper(Ⅰ)-iodide cluster microcubes as a new class of X-ray scintillators.The as-prepared microcubes exhibit remarkable sensitivity to X-rays and exceptional stability under moisture and X-ray exposure.The uniform size distribution and high scintillation performance of the copper(Ⅰ)-iodide cluster microcubes make them suitable for the fabrication of large-area,flexible scintillating films for X-ray imaging applications in both static and dynamic settings.展开更多
Graphene-based flexible transparent electrodes(FTEs)are promising candidate materials for developing next-generation flexible organic light-emitting diodes(OLEDs).However,the quest for high-efficiency OLEDs is hindere...Graphene-based flexible transparent electrodes(FTEs)are promising candidate materials for developing next-generation flexible organic light-emitting diodes(OLEDs).However,the quest for high-efficiency OLEDs is hindered by the low light-extraction and charge injection efficiencies of graphene electrode.Here,we combine the frustrated Lewis pair doping with nanostructure engineering to obtain high-performance graphene FTE.A p-type dopant aci-nitromethane-tris(pentafluorophenyl)borane(ANBCF)was synthesized and deposited on graphene FTE to form an aperiodic nanostructure,which not only improves the light-extraction but also stably p-dopes graphene to enhance its hole injection.The use of ANBCF-doped graphene as the anode enables high-efficiency flexible green OLEDs with external quantum efficiency(EQE)and power efficiency(PE)out-performing most flexible graphene OLEDs of comparable structure.This study provides a simple and effective pathway to fabricate high-performance graphene FTEs for efficient flexible OLEDs.展开更多
For the first time,electroplex emission is utilized to enhance the performance of nondoped blue organic light-emitting diodes(OLEDs).By decorating the twisted blue-emitting platform and adjusting the electronic struct...For the first time,electroplex emission is utilized to enhance the performance of nondoped blue organic light-emitting diodes(OLEDs).By decorating the twisted blue-emitting platform and adjusting the electronic structure,three molecules of 3Cz-Ph-CN,3Cz-mPh-CN,and 3Ph-Cz-CN with a donor-acceptor structure are synthesized and investigated.When external voltage is applied,electroplex emission,which contributes to the emission performance of OLED,can be realized at the interface between the emitting layer and the electron-transporting layer.Accordingly,high external quantum efficiency of 18.1%can be achieved,while the emission wavelength of the device can be controlled in the blue region.Our results provide the possibility to enhance the performance of OLED through electroplex emission,in addition to the generally investigated thermally activated delayed fluorescence(TADF).Excitedly,when 3Ph-Cz-CN is used as host material in orange-emitting phosphorous OLEDs(PO-01 as the dopant),unprecedented high external quantum efficiency of 27.4%can also be achieved.展开更多
Limited to the structure of traditional light‐emitting devices,electronic devices that can directly convert machine language into human visual information without introducing any back‐end circuit are still not easy ...Limited to the structure of traditional light‐emitting devices,electronic devices that can directly convert machine language into human visual information without introducing any back‐end circuit are still not easy to achieve.Based on a specially designed three‐phase co‐planar electrode structure,a new type of three‐phase alternating current driven organic light‐emitting device with the integration of emission and control functions,full‐color tunability and simple device structure is demonstrated in this study.We integrate the light‐emitting function of color‐tunable light‐emitting devices and the switching of three triodes in a single three phase organic light‐emitting device.The state control of luminous color and luminance intensity merely requires the introduction of a kind of machine language,that is an easy‐to‐program 6‐bit binary number coded digital signals.The color adjustable area covers 66%of the color triangle of the National Television System Committee.Such simple and easy‐to‐integrate light‐emitting system has great potential applications in the next‐generation man‐machine interface.展开更多
基金financially supported by the Natural Science Foundation of China(Grant Nos.52372226,52173263,62004167)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant Nos.2022JM-315,2023-JC-QN-0643)+4 种基金the National Key R&D Program of China(Grant No.2022YFB3603703)the Qinchuangyuan High-level Talent Project of Shaanxi(Grant No.QCYRCXM-2022-219)the Ningbo Natural Science Foundation(Grant No.2022J061)the Key Research and Development Program of Shaanxi(Grant No.2023GXLH-091)the Shccig-Qinling Program and the Fundamental Research Funds for the Central Universities。
文摘Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP PSCs.Inspired by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer counterparts.Herein,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are realized.These films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared film.Accordingly,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to date.Importantly,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.
基金financially supported by the National Natural Science Foundation of China(Grants 51972172,61705102,91833304 and 51802253)the Natural Science Basic Research Plan in Shaanxi Province of China(2019JM-326)+5 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z007)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Young 1000 Talents Global Recruitment Program of ChinaJiangsu Specially Appointed Professor program“Six talent peaks”Project in Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universities。
文摘The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovskites with low bandgaps have been rapidly developed,and their single junction solar cells have reached power conversion efficiency(PCE)over 21%,which also makes them ideal candidate as low bandgap sub-cell for tandem device.Nevertheless,due to the incorporation of unstable Sn^(2+),the stability issue becomes the vital problem for the further development of Sn-Pb mixed perovskite solar cells(PSCs).In this review,we are dedicated to give a full view in current understanding on the stability issue of SnPb mixed perovskites and their PSCs.We begin with the demonstration on the origin of instability of Sn-Pb mixed perovskites,including oxidation of Sn^(2+),defects,and interfacial layer induced instability.Sequentially,the up-to-date developments on the stability improvement of Sn-Pb mixed perovskites and their PSCs is systematically reviewed,including composition engineering,additive engineering,and interfacial engineering.At last,the current challenges and future perspectives on the stability study of Sn-Pb mixed PSCs are discussed,which we hope could promote the further application of Sn-Pb mixed perovskites towards commercialization.
基金Z.H.Lu would like to acknowledge the Natural Science and Engineering Research Council of Canada,and the National Natural Science Foundation of China(Grant No.11774304)for providing research fund.H.Y.Yu would like to acknowledge the financial support by Research and Application of Key Technologies of GaN-based Power Devices on Si Substrate(Grant No:2019B010128001)Research on key technologies for optimization of IoT chips and product development(Grant No.2019B010142001)+1 种基金and Study and optimization of electrostatic discharge mechanism for GaN HEMT devices(Grant No:JCYJ20180305180619573)Research of AlGaN HEMT MEMS sensor for work in extreme environment(Grant No:JCYJ20170412153356899).
文摘Thin-film flexible solar cells are lightweight and mechanically robust.Along with rapidly advancing battery technology,flexible solar panels are expected to create niche products that require lightweight,mechanical flexibility,and moldability into complex shapes,such as roof-panel for electric automobiles,foldable umbrellas,camping tents,etc.In this paper,we provide a comprehensive assessment of relevant materials suitable for making flexible solar cells.Substrate materials reviewed include metals,ceramics,glasses,and plastics.For active materials,we focus primarily on emerging new semiconductors including small organic donor/acceptor molecules,conjugated donor/acceptor polymers,and organometal halide perovskites.For electrode materials,transparent conducting oxides,thin metal films/nanowires,nanocarbons,and conducting polymers are reviewed.We also discuss the merits,weaknesses,and future perspectives of these materials for developing next-generation flexible photovoltaics.
基金financially supported by the Natural Science Foundation of China (Grants 51802253, 51972172, 61705102,61904152, and 91833304)the China Postdoctoral Science Foundation (Grant 2021M692630)+6 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (2019JM-326)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (No. 2020GXLH-Z-007)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China (Grant BK20200034)the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially Appointed Professor programthe “Six talent peaks” Project in Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universities。
文摘Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.
基金This work is supported by the National Key and Program of China(grant number 2020YFA0709900)the National Natural Science Foundation of China(grant numbers 22075228 and 62134007)+1 种基金the Joint Research Funds of the Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(grant number 2020GXLH-Z011)the Fundamental Research Funds for the Central Universities(grant numbers 0515023GH0202078 and 0515023SH0201078).
文摘The advancement of contemporary X-ray imaging heavily depends on discovering scintillators that possess high sensitivity,robust stability,low toxicity,and a uniform size distribution.Despite significant progress in this field,the discovery of a material that satisfies all of these criteria remains a challenge.In this study,we report the synthesis of monodisperse copper(Ⅰ)-iodide cluster microcubes as a new class of X-ray scintillators.The as-prepared microcubes exhibit remarkable sensitivity to X-rays and exceptional stability under moisture and X-ray exposure.The uniform size distribution and high scintillation performance of the copper(Ⅰ)-iodide cluster microcubes make them suitable for the fabrication of large-area,flexible scintillating films for X-ray imaging applications in both static and dynamic settings.
基金supported by the National Science Foundation of China(Nos.52272051,52172057,52188101 and 52002375)Ministry of Science and Technology of China(No.2021YFA1200804)+3 种基金Chinese Academy of Sciences(Nos.ZDBSLYJSC027 and XDB30000000)Postdoctoral Science Foundation of China(Nos.2020M670812 and 2020TQ0328)Liaoning Revitalization Talents Program(No.XLYC1808013)Guangdong Basic and Applied Basic Research Foundation(No.2020B0301030002).
文摘Graphene-based flexible transparent electrodes(FTEs)are promising candidate materials for developing next-generation flexible organic light-emitting diodes(OLEDs).However,the quest for high-efficiency OLEDs is hindered by the low light-extraction and charge injection efficiencies of graphene electrode.Here,we combine the frustrated Lewis pair doping with nanostructure engineering to obtain high-performance graphene FTE.A p-type dopant aci-nitromethane-tris(pentafluorophenyl)borane(ANBCF)was synthesized and deposited on graphene FTE to form an aperiodic nanostructure,which not only improves the light-extraction but also stably p-dopes graphene to enhance its hole injection.The use of ANBCF-doped graphene as the anode enables high-efficiency flexible green OLEDs with external quantum efficiency(EQE)and power efficiency(PE)out-performing most flexible graphene OLEDs of comparable structure.This study provides a simple and effective pathway to fabricate high-performance graphene FTEs for efficient flexible OLEDs.
基金the National Science Foundation of China(nos.21734007,51573140,91833304,and 11661131001)Fundamental Research Funds for the Central Universities(2042017kf0247)Hubei Province(2017CFA002)for financial support.
文摘For the first time,electroplex emission is utilized to enhance the performance of nondoped blue organic light-emitting diodes(OLEDs).By decorating the twisted blue-emitting platform and adjusting the electronic structure,three molecules of 3Cz-Ph-CN,3Cz-mPh-CN,and 3Ph-Cz-CN with a donor-acceptor structure are synthesized and investigated.When external voltage is applied,electroplex emission,which contributes to the emission performance of OLED,can be realized at the interface between the emitting layer and the electron-transporting layer.Accordingly,high external quantum efficiency of 18.1%can be achieved,while the emission wavelength of the device can be controlled in the blue region.Our results provide the possibility to enhance the performance of OLED through electroplex emission,in addition to the generally investigated thermally activated delayed fluorescence(TADF).Excitedly,when 3Ph-Cz-CN is used as host material in orange-emitting phosphorous OLEDs(PO-01 as the dopant),unprecedented high external quantum efficiency of 27.4%can also be achieved.
基金supported by the Key‐Area Research and Development Program of Guangdong Province(No.2019B010924003)Guangdong Basic and Applied Basic Research Foundation(No.2020B1515120030,No.2020A1515010449)+3 种基金Natural Science Basic Research Program of Shaanxi(Program No.2019JLP‐11)Shenzhen Fundamental Research Program(JCYJ20190808182803805)Shenzhen OLED Materials and Devices Technology Engineering Research Center([2018]1410)Shenzhen Key Laboratory of Shenzhen Science and Technology(ZDSYS_(2)0140509094114164).
文摘Limited to the structure of traditional light‐emitting devices,electronic devices that can directly convert machine language into human visual information without introducing any back‐end circuit are still not easy to achieve.Based on a specially designed three‐phase co‐planar electrode structure,a new type of three‐phase alternating current driven organic light‐emitting device with the integration of emission and control functions,full‐color tunability and simple device structure is demonstrated in this study.We integrate the light‐emitting function of color‐tunable light‐emitting devices and the switching of three triodes in a single three phase organic light‐emitting device.The state control of luminous color and luminance intensity merely requires the introduction of a kind of machine language,that is an easy‐to‐program 6‐bit binary number coded digital signals.The color adjustable area covers 66%of the color triangle of the National Television System Committee.Such simple and easy‐to‐integrate light‐emitting system has great potential applications in the next‐generation man‐machine interface.
