Previous reports of formamidinium/methylamine(FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example,through the inclusion of ...Previous reports of formamidinium/methylamine(FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example,through the inclusion of bromine and surface passivation.In this paper,we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase.Through low-temperature aging growth(LTAG)of a freshly deposited perovskite film,α-phase perovskites can be seeded in the intermediate phase and,at the same time,prevent beta-phase perovskite to nucleate.After postannealing,large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained,thereby eliminating the need of additional surface passivation step.Our pristine LTAG-treated solar cells could provide PCEs of greater than 22%without elaborate use of bromine or an additional passivation layer.More importantly,when using this LTAG process,the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.展开更多
In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,name...In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,namely1-(p-benzoate-(p-methylvinylbenzene)-indolino[2,3][60]fullerene(FPPS),was readily synthesized from commercially available building blocks in two steps.This FPPS was employed as an interfacial modifier on perovskite surfaces in inverted planar p-i-n PSCs.Owing to the fast interfacial charge extraction and efficient trap passivation,PSCs based on the cross-linked FPPS(C-FPPS)exhibited excellent performance.The PSCs had a top-performing power conversion efficiency(PCE)of 17.82%with negligible hysteresis,compared to the control devices without C-PFFS(16.99%).Moreover,the strong water resistance of the C-FPPS interfacial layer distinctly enhances the ambient stability of PSC devices,exhibiting a t80(the time required to reach 80%of the initial PCE)of 300 h under high-humidity conditions.This significantly surpasses the control devices,whose t80 was only 130 h.These results demonstrate that cross-linkable fullerene derivatives can be promising interfacial materials for designing high-efficiency,hysteresis-free,air-stable PSCs.展开更多
Despite the many advantages for industrial mass production,vacuum-deposited organic solar cells(OSCs)suffer from low efficiency,primarily due to the limited molecular library of small-molecule donor and acceptor mater...Despite the many advantages for industrial mass production,vacuum-deposited organic solar cells(OSCs)suffer from low efficiency,primarily due to the limited molecular library of small-molecule donor and acceptor materials,which remains a significant challenge.Herein,two donor–acceptor-acceptor(D-A-A)-configured small-molecule donors,named TTBTDC and TTBTDC-F were synthesized,using 8H-thieno[2′,3′:4,5]thieno[3,2-b]thieno[2,3-d]pyrrole(TTP)as a new fused-ring donor unit.Benefiting from the strong electron-donating ability of the TTP moiety and the adoption of the D-A-A molecular configuration,these molecules exhibited strong visible and near-infrared absorption as well as deep-lying highest occupied molecular orbital(HOMO)energy levels.Consequently,OSCs based on TTBTDC achieved an unprecedented power conversion efficiency(PCE)of 10.28%(certified value of 10.05%)with a short-circuit current density(J_(sc))up to 17.78 mA cm^(−2),representing the highest PCE and J_(sc)values reported to date for vacuum-deposited OSCs.In contrast,OSCs based on TTBTDC-F exhibited an inferior PCE of 8%with slightly higher open-circuit voltage(V_(oc))but lower J_(sc).By systematically investigating the relationships between molecular structure and properties,we found that the high performance of TTBTDC devices results from extended absorption up to 900 nm,stronger cofacial antiparallelπ-πinteractions,and superior charge transport with suppressed recombination.Besides,both TTBTDC and TTBTDC-F devices exhibited excellent device stabilities,including storage stability,thermal stability,and photo-stability.This work demonstrates the great potential of TTP as a building block for constructing small-molecule donors and sheds light on the molecular design of small-molecule donors for high-efficiency and stable vacuum-deposited OSCs.展开更多
Two stereomers of bisadduct analogues of [6, 6]-phenyl-C71-butyric acid methyl ester （bisPC71BM） were synthesized and their geometrical structures with cis- or trans-configuration were identified by X-ray crystallog...Two stereomers of bisadduct analogues of [6, 6]-phenyl-C71-butyric acid methyl ester （bisPC71BM） were synthesized and their geometrical structures with cis- or trans-configuration were identified by X-ray crystallogra- phy. Although both of the bisPC71BM have similar spec- trometric and electrochemical properties, the spatial orientation of the two addition groups on C7o has impact on crystal packing and molecular assembly of bisPC71BM isomers and, in turn, photovoltaic performance in polymer solar cell based on poly（3-hexylthiophene） （P3HT） （with power conversion efficiency of 1.72 % and 1.84 % for the solar cells involving cis- and trans-bisPC71BM, respec- tively）. Although the power conversion efficiency remains to be improved, this work exemplifies that the photovoltaic properties of fullerene-based electron acceptors areinfluenced by aggregation of the stereomeric molecules and thus extends the guidelines for rational design of efficient fullerene acceptor.展开更多
It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investiga...It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investigation is made to reveal the mechanism behind from detailed photophysical processes in performed cells. The results show that the crystal packings of isomers affect the electron mobilities dominantly from the electronic coupling for electron transfer, and the trends of calculated mobilities are consistent with experimental measurements although the magnitudes are obviously larger. For the performed cells from two isomers with poly(3-hexylthiophene) as a donor, it is found that the exciton dissociation yields are also different, manifesting that stereometric packings essentially control the cell efficiency via both electron mobilities and exciton dissociation. Furthermore,the reasons for low cell efficiencies are analyzed, and possible improvements are suggested.展开更多
基金funded partly by the National Natural Science Foundation of China(Grant No.51950410581)the Shanghai Pujiang Program+2 种基金the Open Fund of Zhejiang Tsinghua Institute of Flexible Electronics Technologyfunding from the National Natural Science Foundation of China(Grant No.21604053)funding from the ECNU Multifunctional Platform for Innovation(003,006).
文摘Previous reports of formamidinium/methylamine(FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example,through the inclusion of bromine and surface passivation.In this paper,we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase.Through low-temperature aging growth(LTAG)of a freshly deposited perovskite film,α-phase perovskites can be seeded in the intermediate phase and,at the same time,prevent beta-phase perovskite to nucleate.After postannealing,large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained,thereby eliminating the need of additional surface passivation step.Our pristine LTAG-treated solar cells could provide PCEs of greater than 22%without elaborate use of bromine or an additional passivation layer.More importantly,when using this LTAG process,the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.
基金the National Natural Science Foundation of China(Nos.21721001,51572231 and 51502252)the Natural Science Foundation of Fujian Province of China(No.2016J01264)。
文摘In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,namely1-(p-benzoate-(p-methylvinylbenzene)-indolino[2,3][60]fullerene(FPPS),was readily synthesized from commercially available building blocks in two steps.This FPPS was employed as an interfacial modifier on perovskite surfaces in inverted planar p-i-n PSCs.Owing to the fast interfacial charge extraction and efficient trap passivation,PSCs based on the cross-linked FPPS(C-FPPS)exhibited excellent performance.The PSCs had a top-performing power conversion efficiency(PCE)of 17.82%with negligible hysteresis,compared to the control devices without C-PFFS(16.99%).Moreover,the strong water resistance of the C-FPPS interfacial layer distinctly enhances the ambient stability of PSC devices,exhibiting a t80(the time required to reach 80%of the initial PCE)of 300 h under high-humidity conditions.This significantly surpasses the control devices,whose t80 was only 130 h.These results demonstrate that cross-linkable fullerene derivatives can be promising interfacial materials for designing high-efficiency,hysteresis-free,air-stable PSCs.
基金supported by the National Natural Science Foundation of China(92361303,92061204,and 52203228)the Natural Science Foundation of Guangdong Province of China(2023A1515011916)+1 种基金the China Postdoctoral Science Foundation(2022M712658)Han Young Woo acknowledges the financial support from the National Research Foundation of Korea(2019R1A6A1A11044070,and RS-2024-00334832).
文摘Despite the many advantages for industrial mass production,vacuum-deposited organic solar cells(OSCs)suffer from low efficiency,primarily due to the limited molecular library of small-molecule donor and acceptor materials,which remains a significant challenge.Herein,two donor–acceptor-acceptor(D-A-A)-configured small-molecule donors,named TTBTDC and TTBTDC-F were synthesized,using 8H-thieno[2′,3′:4,5]thieno[3,2-b]thieno[2,3-d]pyrrole(TTP)as a new fused-ring donor unit.Benefiting from the strong electron-donating ability of the TTP moiety and the adoption of the D-A-A molecular configuration,these molecules exhibited strong visible and near-infrared absorption as well as deep-lying highest occupied molecular orbital(HOMO)energy levels.Consequently,OSCs based on TTBTDC achieved an unprecedented power conversion efficiency(PCE)of 10.28%(certified value of 10.05%)with a short-circuit current density(J_(sc))up to 17.78 mA cm^(−2),representing the highest PCE and J_(sc)values reported to date for vacuum-deposited OSCs.In contrast,OSCs based on TTBTDC-F exhibited an inferior PCE of 8%with slightly higher open-circuit voltage(V_(oc))but lower J_(sc).By systematically investigating the relationships between molecular structure and properties,we found that the high performance of TTBTDC devices results from extended absorption up to 900 nm,stronger cofacial antiparallelπ-πinteractions,and superior charge transport with suppressed recombination.Besides,both TTBTDC and TTBTDC-F devices exhibited excellent device stabilities,including storage stability,thermal stability,and photo-stability.This work demonstrates the great potential of TTP as a building block for constructing small-molecule donors and sheds light on the molecular design of small-molecule donors for high-efficiency and stable vacuum-deposited OSCs.
基金supported by the National Basic Research Program of China(2014CB845601)the National Natural Science Foundation of China(U1205111+3 种基金2139039051572231and51502252)the Fundamental Research Funds for the Central Universities(20720140512)
文摘Two stereomers of bisadduct analogues of [6, 6]-phenyl-C71-butyric acid methyl ester （bisPC71BM） were synthesized and their geometrical structures with cis- or trans-configuration were identified by X-ray crystallogra- phy. Although both of the bisPC71BM have similar spec- trometric and electrochemical properties, the spatial orientation of the two addition groups on C7o has impact on crystal packing and molecular assembly of bisPC71BM isomers and, in turn, photovoltaic performance in polymer solar cell based on poly（3-hexylthiophene） （P3HT） （with power conversion efficiency of 1.72 % and 1.84 % for the solar cells involving cis- and trans-bisPC71BM, respec- tively）. Although the power conversion efficiency remains to be improved, this work exemplifies that the photovoltaic properties of fullerene-based electron acceptors areinfluenced by aggregation of the stereomeric molecules and thus extends the guidelines for rational design of efficient fullerene acceptor.
基金partially supported by the National Natural Science Foundation of China(9133310121133007+1 种基金21573175)the support from Scientific Research Foundation of Henan University(B2013141)
文摘It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investigation is made to reveal the mechanism behind from detailed photophysical processes in performed cells. The results show that the crystal packings of isomers affect the electron mobilities dominantly from the electronic coupling for electron transfer, and the trends of calculated mobilities are consistent with experimental measurements although the magnitudes are obviously larger. For the performed cells from two isomers with poly(3-hexylthiophene) as a donor, it is found that the exciton dissociation yields are also different, manifesting that stereometric packings essentially control the cell efficiency via both electron mobilities and exciton dissociation. Furthermore,the reasons for low cell efficiencies are analyzed, and possible improvements are suggested.
