Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 ...Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 in acceptors. The over 8% PCE improvement by employing ternary strategy is attributed to the simultaneously increased JSCof 25.68 mA cm^-2, VOCof 0.853 V and FF of 78.61% compared with Y6 based binary PSCs. The good compatibility of MF1 and Y6 can be confirmed from Raman mapping, contact angle,cyclic voltammetry and morphology, which is the prerequisite to form alloy-like state. Electron mobility in ternary active layers strongly depends on MF1 content in acceptors due to the different lowest unoccupied molecular orbital(LUMO) levels of Y6 and MF1, which can well explain the wave-like varied FF of ternary PSCs. The third-party certified PCE of 16.8% should be one of the highest values for single bulk heterojunction PSCs. This work provides sufficient references for selecting materials to achieve efficient ternary PSCs.展开更多
Introducing liquid-crystalline small-molecule donors(SMDs)into binary systems based on the strong intermolecular interactions of SMDs is a facile and effective strategy to tune the active layer morphology and improve ...Introducing liquid-crystalline small-molecule donors(SMDs)into binary systems based on the strong intermolecular interactions of SMDs is a facile and effective strategy to tune the active layer morphology and improve the performance of organic solar cells(OSCs).Contrary to conventional understanding,this research proposes a new strategy for ternary OSCs implicating that"weakly crystalline materials can also optimize the morphology of the active layer and improve the OSCs performance".Herein,we designed and synthesized two liquid-crystalline SMDs,Z1 and Z2,based on benzodifuran(BDF)units.The amorphous Z2-incorporated ternary devices present an unexpectedly improved power conversion efficiency(PCE)>18%with good stability.By contrast,the highly ordered Z1-based ternary devices possess a significantly depressed efficiency.Multiple characterizations reveal that the Z2-based ternary blend films possess improved miscibility and efficient charge transport.This novel strategy for the selection of the third component is significant for the fabrication of high-efficiency ternary OSCs.展开更多
A series of organic photovoltaic （PV） cells in which the electron acceptor and donor are gadolinium （dibenzoylmethanato）3（bathophenanthroline） and N,N′-diphenyl-N,N′bis（3-methylphenyl）-1,1′-diphenyl-4,4′-d...A series of organic photovoltaic （PV） cells in which the electron acceptor and donor are gadolinium （dibenzoylmethanato）3（bathophenanthroline） and N,N′-diphenyl-N,N′bis（3-methylphenyl）-1,1′-diphenyl-4,4′-diamine , respectively, were fabricated. Although TPD acts as an active layer in the bilayered cells, insertion of a Gd-complex film between TPD and the alloy cathode is necessary for efficient carrier photogeneration. Open-circuit voltage of 3.2 V is obtained due to efficient exciton dissociation near the interface between （Gd（DBM）3bath） and TPD. By incorporating an ultrathin mixed layer of Gd-complex and TPD, external quantum efficiency is improved significantly.It was found that photovoltaic performance of the devices has a common origin, exciplex formation, which results in broadband emission during both photoluminescent and the electroluminescent processes.展开更多
采用单光子计数法(Time Correlated Single Photon Counting,TCSPC)测量了MEH-PPV和CdS共混薄膜退火处理前后受到超短脉冲激光激发及光生载流子的瞬态衰减过程,得到了MEH-PPV:CdS共混薄膜材料的光生载流子寿命。分析表明,退火处理后MEH-...采用单光子计数法(Time Correlated Single Photon Counting,TCSPC)测量了MEH-PPV和CdS共混薄膜退火处理前后受到超短脉冲激光激发及光生载流子的瞬态衰减过程,得到了MEH-PPV:CdS共混薄膜材料的光生载流子寿命。分析表明,退火处理后MEH-PPV:CdS共混薄膜材料的光生载流子寿命更长,相应的光伏器件(结构为ITO/PEDOT:PSS/MEH-PPV:CdS/Al的有机薄膜光伏器件)也具有较高的光电转换效率。展开更多
基金This work was supported by the National Natural Science Foundation of China(61805009,61675017,61975006)China Postdoctoral Science Foundation(2018M641170)+1 种基金Beijing Natural Science Foundation(4192049)The authors gratefully acknowledge the assistance of the Shanghai Synchrotron Radiation Facility(beamline BL16B1)for GWAIXS and GISAXS measurements.
文摘Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 in acceptors. The over 8% PCE improvement by employing ternary strategy is attributed to the simultaneously increased JSCof 25.68 mA cm^-2, VOCof 0.853 V and FF of 78.61% compared with Y6 based binary PSCs. The good compatibility of MF1 and Y6 can be confirmed from Raman mapping, contact angle,cyclic voltammetry and morphology, which is the prerequisite to form alloy-like state. Electron mobility in ternary active layers strongly depends on MF1 content in acceptors due to the different lowest unoccupied molecular orbital(LUMO) levels of Y6 and MF1, which can well explain the wave-like varied FF of ternary PSCs. The third-party certified PCE of 16.8% should be one of the highest values for single bulk heterojunction PSCs. This work provides sufficient references for selecting materials to achieve efficient ternary PSCs.
基金the Ministry of Science and Technology of China(2017YFA0204504)the National Natural Science Foundation of China(51873221,52073292,51673207,21774003,and 51373183)+2 种基金Chinese Academy of Sciences and Dutch Research Project(1A111KYSB20190072)Beijing Municipal Science&Technology Commission(Z181100004418012)Beijing Natural Science Foundation(2212032).
文摘Introducing liquid-crystalline small-molecule donors(SMDs)into binary systems based on the strong intermolecular interactions of SMDs is a facile and effective strategy to tune the active layer morphology and improve the performance of organic solar cells(OSCs).Contrary to conventional understanding,this research proposes a new strategy for ternary OSCs implicating that"weakly crystalline materials can also optimize the morphology of the active layer and improve the OSCs performance".Herein,we designed and synthesized two liquid-crystalline SMDs,Z1 and Z2,based on benzodifuran(BDF)units.The amorphous Z2-incorporated ternary devices present an unexpectedly improved power conversion efficiency(PCE)>18%with good stability.By contrast,the highly ordered Z1-based ternary devices possess a significantly depressed efficiency.Multiple characterizations reveal that the Z2-based ternary blend films possess improved miscibility and efficient charge transport.This novel strategy for the selection of the third component is significant for the fabrication of high-efficiency ternary OSCs.
文摘A series of organic photovoltaic （PV） cells in which the electron acceptor and donor are gadolinium （dibenzoylmethanato）3（bathophenanthroline） and N,N′-diphenyl-N,N′bis（3-methylphenyl）-1,1′-diphenyl-4,4′-diamine , respectively, were fabricated. Although TPD acts as an active layer in the bilayered cells, insertion of a Gd-complex film between TPD and the alloy cathode is necessary for efficient carrier photogeneration. Open-circuit voltage of 3.2 V is obtained due to efficient exciton dissociation near the interface between （Gd（DBM）3bath） and TPD. By incorporating an ultrathin mixed layer of Gd-complex and TPD, external quantum efficiency is improved significantly.It was found that photovoltaic performance of the devices has a common origin, exciplex formation, which results in broadband emission during both photoluminescent and the electroluminescent processes.
文摘采用单光子计数法(Time Correlated Single Photon Counting,TCSPC)测量了MEH-PPV和CdS共混薄膜退火处理前后受到超短脉冲激光激发及光生载流子的瞬态衰减过程,得到了MEH-PPV:CdS共混薄膜材料的光生载流子寿命。分析表明,退火处理后MEH-PPV:CdS共混薄膜材料的光生载流子寿命更长,相应的光伏器件(结构为ITO/PEDOT:PSS/MEH-PPV:CdS/Al的有机薄膜光伏器件)也具有较高的光电转换效率。
