A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for hi...A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.展开更多
This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications.We first present a brief introduction of the fundamental principles of polym...This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications.We first present a brief introduction of the fundamental principles of polymer solar cells,and then the functions of fluorine atoms on the polymer donor materials.Finally,we review the research progress of the reported copolymers by classification of the fluorinated acceptor units and donor units,respectively.The resulting structure-property correlations of these copolymers are also discussed which shall certainly facilitate widespread utilization of this strategy for constructing high-performance photovoltaic copolymers in the future.展开更多
Two lowly fused non-fullerene acceptors(NFAs)with isomeric structures,named as BTP-out-4F and BTP-in-4F,were developed by tailoring the fused 7-ring central core of Y6 into a lowly fused 5-ring linked with two octylox...Two lowly fused non-fullerene acceptors(NFAs)with isomeric structures,named as BTP-out-4F and BTP-in-4F,were developed by tailoring the fused 7-ring central core of Y6 into a lowly fused 5-ring linked with two octyloxythiophene bridges.BTP-out-4F with octyloxy side chains away from the central core exhibited large steric hindrance that restrained the rotational freedom between the thiophene bridge and end group but maintained free rotation between the central core and the thiophene bridge.In contrast,BTP-in-4F with octyloxy side chains close to the central core had much lower rotation freedom due to the non-covalent S⋯O interactions locked the central core,thiophene bridge and end group simultaneously,making BTP-in-4F have higher molecular crystallinity.On the other hand,the optical properties,energy levels and the blend morphology properties were significantly influenced,leading to distinctive photovoltaic performances.BTP-out-4F formed favorable energy level alignment and morphology when matching with PBDB-T donor,thus its device realized a much higher PCE of 13.32%,which was over 13 times than that of BTP-in-4F based device(PCE=0.97%).展开更多
Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largea...Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51573107 and 21432005)the Youth Science and Technology Foundation of Sichuan Province(No.2013JQ0032)+2 种基金the Foundation of State Key Laboratory of Polymer Materials Engineering(sklpme2014-3-05)the Synergistic Innovation Joint Foundation of CAEPSCU(No.XTCX2014008)the Fundamental Research Funds for the Central Universities(Nos.2012SCU04B01 and YJ2011025)
文摘A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.
基金supported by the NSFC(Nos.51573107,21432005)the Youth Science and Technology Foundation of Sichuan Province(No.2013JQ0032)+2 种基金the Foundation of State Key Laboratory of Polymer Materials Engineering(Nos.sklpme2014-3-05,sklpme2015-2-01)the Synergistic Innovation Joint Foundation of CAEP-SCU(No.XTCX2014008)the Fundamental Research Funds for the Central Universities(Nos.2012SCU04B01,YJ2011025)
文摘This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications.We first present a brief introduction of the fundamental principles of polymer solar cells,and then the functions of fluorine atoms on the polymer donor materials.Finally,we review the research progress of the reported copolymers by classification of the fluorinated acceptor units and donor units,respectively.The resulting structure-property correlations of these copolymers are also discussed which shall certainly facilitate widespread utilization of this strategy for constructing high-performance photovoltaic copolymers in the future.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21825502,22075190,21905185 and 22105135)Special funds for local science and technology development guided by the central government(No.2020ZYD004)+1 种基金the Foundation of State Key Laboratory of Polymer Materials Engineering(No.SKLPME 2017-2-04)the Fundamental Research Funds for the Central Universities.
文摘Two lowly fused non-fullerene acceptors(NFAs)with isomeric structures,named as BTP-out-4F and BTP-in-4F,were developed by tailoring the fused 7-ring central core of Y6 into a lowly fused 5-ring linked with two octyloxythiophene bridges.BTP-out-4F with octyloxy side chains away from the central core exhibited large steric hindrance that restrained the rotational freedom between the thiophene bridge and end group but maintained free rotation between the central core and the thiophene bridge.In contrast,BTP-in-4F with octyloxy side chains close to the central core had much lower rotation freedom due to the non-covalent S⋯O interactions locked the central core,thiophene bridge and end group simultaneously,making BTP-in-4F have higher molecular crystallinity.On the other hand,the optical properties,energy levels and the blend morphology properties were significantly influenced,leading to distinctive photovoltaic performances.BTP-out-4F formed favorable energy level alignment and morphology when matching with PBDB-T donor,thus its device realized a much higher PCE of 13.32%,which was over 13 times than that of BTP-in-4F based device(PCE=0.97%).
基金the National Natural Science Foundation of China(NSFC,21825502)the Foundation of State Key Laboratory of Polymer Materials Engineering(SKLPME 2017-2-04)the Fundamental Research Funds for the Central Universities。
文摘Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.
