Mixed Sn-Pb perovskites are attracting significant attention due to their narrow bandgap and consequent potential for all-perovskite tandem solar cells.However,the conventional hole transport materials can lead to ban...Mixed Sn-Pb perovskites are attracting significant attention due to their narrow bandgap and consequent potential for all-perovskite tandem solar cells.However,the conventional hole transport materials can lead to band misalignment or induce degradation at the buried interface of perovskite.Here we designed a self-assembled material 4-(9H-carbozol-9-yl)phenylboronic acid(4PBA)for the surface modification of the substrate as the hole-selective contact.It incorporates an electron-rich carbazole group and conjugated phenyl group,which contribute to a substantial interfacial dipole moment and tune the substrate’s energy levels for better alignment with the Sn-Pb perovskite energy levels,thereby promoting hole extraction.Meanwhile,enhanced perovskite crystallization and improved contact at bottom of the perovskite minimized defects within perovskite bulk and at the buried interface,suppressing non-radiative recombination.Consequently,Sn-Pb perovskite solar cells using 4PBA achieved efficiencies of up to 23.45%.Remarkably,the 4PBA layer provided superior interfacial chemical stability,and effectively mitigated device degradation.Unencapsulated devices retained 93.5%of their initial efficiency after 2000 h of shelf storage.展开更多
Charge-transporting layers(CTLs)are important in determining the performance and stability of perovskite solar cells(PSCs).Recently,there has been considerable use of self-assembled monolayers(SAMs)as charge-selective...Charge-transporting layers(CTLs)are important in determining the performance and stability of perovskite solar cells(PSCs).Recently,there has been considerable use of self-assembled monolayers(SAMs)as charge-selective contacts,especially for hole-selective SAMs in inverted PSCs as well as perovskite involving tandem solar cells.The SAM-based charge-selective contact shows many advantages over traditional thin-film organic/inorganic CTLs,including reduced cost,low optical and electric loss,conformal coating on a rough substrate,simple deposition on a large-area substrate and easy modulation of energy levels,molecular dipoles and surface properties.The incorporation of various hole-selective SAMs has resulted in high-efficiency single junction and tandem solar cells.This topical review summarizes both the advantages and challenges of SAM-based charge-selective contacts,and discusses the potential direction for future studies.展开更多
The precisely customizable attributes of self-assembled monolayers(SAMs)molecules at the atomic level hold the potential to facilitate efficient hole selection and interface passivation simultaneously.However,the corr...The precisely customizable attributes of self-assembled monolayers(SAMs)molecules at the atomic level hold the potential to facilitate efficient hole selection and interface passivation simultaneously.However,the correlation between the exposure of passivating groups on the surface and device performance remains unexplored.Herein,we introduce two newly designed SAM molecules,Cbz2S and Cbz2SMe,incorporating cyclic disulfide or two flanking thiomethyls by modifying the 4,5-position of carbazole to adjust the Lewis basicity of the SAM-modified surface.Despite possessing suitable energetic alignment,Cbz2S with more-exposed sulfur atoms exhibited inferior device performance due to excessive reactivity,leading to an overpopulation of PbI2 crystallites at the buried perovskite interface.In contrast,the screening effect from the methyl groups of Cbz2SMe optimized SAM reactivity,exquisitely integrating buried interface passivation and hole selection together.Consequently,the champion inverted perovskite solar cell(PSC)employing Cbz2SMe achieved an impressive power conversion efficiency of 24.42%,accompanied by prolonged stability.This work demonstrates the feasibility of incorporating Lewis-basic passivation groups into SAM molecules and elucidates the relationship between the reactivity of SAM passivation groups and device performance.These findings provide valuable insights for the design of novel multifunctional SAM molecules,further advancing the performance of PSCs.展开更多
Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))...Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 V.Herein,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and substrate.The assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase separation.The energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 sunlight.The V_(OC)-deficit(<0.40 V)is the lowest value reported for WBG-PSCs.This work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.展开更多
Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in ...Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.展开更多
基金supported by the Joint Fund of Provincial Science and Technology Research and Development Plan of Henan Province(232301420004)and the Outstanding Youth Fund of the Natural Science Foundation of Henan Province(242300421069)the Energy for future-E4F Postdoctoral fellowship program MSCA-COFUND(101034297).
文摘Mixed Sn-Pb perovskites are attracting significant attention due to their narrow bandgap and consequent potential for all-perovskite tandem solar cells.However,the conventional hole transport materials can lead to band misalignment or induce degradation at the buried interface of perovskite.Here we designed a self-assembled material 4-(9H-carbozol-9-yl)phenylboronic acid(4PBA)for the surface modification of the substrate as the hole-selective contact.It incorporates an electron-rich carbazole group and conjugated phenyl group,which contribute to a substantial interfacial dipole moment and tune the substrate’s energy levels for better alignment with the Sn-Pb perovskite energy levels,thereby promoting hole extraction.Meanwhile,enhanced perovskite crystallization and improved contact at bottom of the perovskite minimized defects within perovskite bulk and at the buried interface,suppressing non-radiative recombination.Consequently,Sn-Pb perovskite solar cells using 4PBA achieved efficiencies of up to 23.45%.Remarkably,the 4PBA layer provided superior interfacial chemical stability,and effectively mitigated device degradation.Unencapsulated devices retained 93.5%of their initial efficiency after 2000 h of shelf storage.
基金supported by the National Natural Science Foundation of China(Grant No.22179037)the Fundamental Research Funds for the Central Universities.Thanks for the financial support of‘Zhang Jiangshu’cultivation program.The authors declare no competing interests.
文摘Charge-transporting layers(CTLs)are important in determining the performance and stability of perovskite solar cells(PSCs).Recently,there has been considerable use of self-assembled monolayers(SAMs)as charge-selective contacts,especially for hole-selective SAMs in inverted PSCs as well as perovskite involving tandem solar cells.The SAM-based charge-selective contact shows many advantages over traditional thin-film organic/inorganic CTLs,including reduced cost,low optical and electric loss,conformal coating on a rough substrate,simple deposition on a large-area substrate and easy modulation of energy levels,molecular dipoles and surface properties.The incorporation of various hole-selective SAMs has resulted in high-efficiency single junction and tandem solar cells.This topical review summarizes both the advantages and challenges of SAM-based charge-selective contacts,and discusses the potential direction for future studies.
基金support from the CityU Infrastructure Support from Central (APRCgrant nos.9380086,9610419,9610492,and 9610508)of the City University of Hong Kong+5 种基金the Guangdong-Hong Kong Technology Cooperation Funding Scheme (TCFS,grant no.GHP/018/20SZ)Midstream Research Programme for Universities (MRP)Grant (grant no.MRP/040/21X)from the Innovation and Technology Commission of Hong Kongthe Green Tech Fund (grant no.202020164)from the Environment and Ecology Bureau of Hong Kongthe General Research Fund (GRF,grant nos.11307621 and 11316422)from the Research Grants Council of Hong KongShenzhen Science and Technology Program (grant no.SGDX20201103095412040)Guangdong Major Project of Basic and Applied Basic Research (grant no.2019B030302007).
文摘The precisely customizable attributes of self-assembled monolayers(SAMs)molecules at the atomic level hold the potential to facilitate efficient hole selection and interface passivation simultaneously.However,the correlation between the exposure of passivating groups on the surface and device performance remains unexplored.Herein,we introduce two newly designed SAM molecules,Cbz2S and Cbz2SMe,incorporating cyclic disulfide or two flanking thiomethyls by modifying the 4,5-position of carbazole to adjust the Lewis basicity of the SAM-modified surface.Despite possessing suitable energetic alignment,Cbz2S with more-exposed sulfur atoms exhibited inferior device performance due to excessive reactivity,leading to an overpopulation of PbI2 crystallites at the buried perovskite interface.In contrast,the screening effect from the methyl groups of Cbz2SMe optimized SAM reactivity,exquisitely integrating buried interface passivation and hole selection together.Consequently,the champion inverted perovskite solar cell(PSC)employing Cbz2SMe achieved an impressive power conversion efficiency of 24.42%,accompanied by prolonged stability.This work demonstrates the feasibility of incorporating Lewis-basic passivation groups into SAM molecules and elucidates the relationship between the reactivity of SAM passivation groups and device performance.These findings provide valuable insights for the design of novel multifunctional SAM molecules,further advancing the performance of PSCs.
基金supported by the National Natural Science Foundation of China(22179037)Shanghai pilot program for Basic Research(22TQ1400100-1)+3 种基金Shanghai Municipal Science and Technology Major Project(2018SHZDZX03,21JC1401700)the Programmer of Introducing Talents of Discipline to Universities(B16017)the Fundamental Research Funds for the Central Universitiessupport from Royal Society of Chemistry(R23-0749928359)。
文摘Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 V.Herein,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and substrate.The assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase separation.The energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 sunlight.The V_(OC)-deficit(<0.40 V)is the lowest value reported for WBG-PSCs.This work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.
基金the National Natural Science Foundation of China(51925206,U1932214,52302052)the National Natural Science Foundation of China(52322318)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(WK2060000051,20720220009)the National Key Research and Development Program of China(No.2023YFB3809700)the Innovation and Technology Fund(GHP/100/20SZ,GHP/102/20GD,MRP/040/21X,ITS/147/22FP)the Research Grants Council of Hong Kong Grant(N_City U102/23,C4005-22Y,C1055-23G,11306521)the Green Tech Fund(GTF202020164)the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20210823104002015,JCYJ20220818101018038)。
文摘Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.
