Bulk heterojunction,non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated.The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additiv...Bulk heterojunction,non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated.The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives(1,3-propanedithiol,1,4-butanedithiol,and 1,8-octanedithiol).It is found that the donor and acceptor are phase separated with different crystalline domains.The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain,benefiting the generation and dissociation of exciton and reducing charge recombination.A substantial improvement in power conversion efficiency of the devices from 8.13%to 9.44%is observed.This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.展开更多
Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy...Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy fabrication. Three D—A—D—A type organic semiconductors(WS-31,WS-32 and WS-52) are synthesized, based on the indoline donor and benzotriazole auxiliary acceptor core, along with either bare thiophene or rigid cyclopentadithiophene as π bridge, rhodanine or carbonocyanidate as end-group. Their HOMO orbitals are delocalized throughout the whole molecules. Whereas the LUMOs are mainly localized on the acceptor part of structure, which reach up to benzothiadiazole, but no distribution on indoline donor. The first excitations for WS-31 and WS-32 are mainly originated by electron transition from HOMO to LUMO level, while for WS-52, partly related to transition between HOMO and LUMO+1 level. The small organic molecules are applied as donor components in bulk heterojunction(BHJ) organic solar cells, using PC_(61)BM as acceptor material to check their photovoltaic performances. The BHJ solar cells based on blended layer of WS-31:PC_(61)BM and WS-32:PC_(61)BM processed with chloroform show overall photoelectric conversion efficiency(PCE) of 0.56% and 1.02%, respectively. WS-32 based BHJ solar cells show a higher current density originated by its relatively larger driving force of photo-induced carrier in photo-active layer to LUMO of PC_(61)BM.展开更多
The development of organic solar cells(OSCs) has focused on optimizing donor and acceptor materials and their morphology in bulk heterojunctions(BHJs), leading to efficiencies over 20% [1-6].
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474017,61574014, and 61874008)
文摘Bulk heterojunction,non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated.The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives(1,3-propanedithiol,1,4-butanedithiol,and 1,8-octanedithiol).It is found that the donor and acceptor are phase separated with different crystalline domains.The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain,benefiting the generation and dissociation of exciton and reducing charge recombination.A substantial improvement in power conversion efficiency of the devices from 8.13%to 9.44%is observed.This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.
基金supported by the NSFC for Creative Research Groups(21421004)Distinguished Young Scholars(21325625)+4 种基金NSFC/China,Science and Technology Commission of Shanghai Municipality(14YF1410500 and 15XD1501400)Shanghai Young Teacher Supporting Foundation(ZZEGD14011)Program for Professor of Special Appointment(Eastern Scholar)"Shu Guang" project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(13SG55)Grants of computing timeat the C3SE supercomputing Center at Chalmers(Gteborg)
文摘Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy fabrication. Three D—A—D—A type organic semiconductors(WS-31,WS-32 and WS-52) are synthesized, based on the indoline donor and benzotriazole auxiliary acceptor core, along with either bare thiophene or rigid cyclopentadithiophene as π bridge, rhodanine or carbonocyanidate as end-group. Their HOMO orbitals are delocalized throughout the whole molecules. Whereas the LUMOs are mainly localized on the acceptor part of structure, which reach up to benzothiadiazole, but no distribution on indoline donor. The first excitations for WS-31 and WS-32 are mainly originated by electron transition from HOMO to LUMO level, while for WS-52, partly related to transition between HOMO and LUMO+1 level. The small organic molecules are applied as donor components in bulk heterojunction(BHJ) organic solar cells, using PC_(61)BM as acceptor material to check their photovoltaic performances. The BHJ solar cells based on blended layer of WS-31:PC_(61)BM and WS-32:PC_(61)BM processed with chloroform show overall photoelectric conversion efficiency(PCE) of 0.56% and 1.02%, respectively. WS-32 based BHJ solar cells show a higher current density originated by its relatively larger driving force of photo-induced carrier in photo-active layer to LUMO of PC_(61)BM.
文摘The development of organic solar cells(OSCs) has focused on optimizing donor and acceptor materials and their morphology in bulk heterojunctions(BHJs), leading to efficiencies over 20% [1-6].
