低聚合度的交替共聚物太阳能电池的形态和性能

制备了由低聚合度的聚2,6-(4,4-双-(2-乙基己基)-4H-环戊2,1-b;3,4-b']双噻吩)-交替-4,7-(2,1,3-苯并噻二唑)](LDP-PCPDTBT)、6,6]-苯基-C61-丁酸甲酯(PC61BM)和聚甲基丙烯酸甲酯(PMMA)组成的三组分共混薄膜,并通过加入溶剂添加剂(1,8-二溴辛烷,DBO)对体系进行了优化处理.研究发现,没有加入DBO时,LDP-PCPDTBT和PC61BM相在PMMA的基质中分别是无定形的和结晶的;加入DBO后,PMMA基质中LDP-PCPDTBT和PC61BM间的相分离过程得到优化,有机太阳能电池的能量转换效率相应提高了32.4%.

MORPHOLOGIES AND PERFORMANCE OF ORGANIC SOLAR CELLS USING LOW POLYMERIZATION DEGREE ALTERNATING COPOLYMER

The ternary blend films composed of low polymerization degree poly2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)](LDP-PCPDTBT),-phenyl-C61-butyric acid methyl ester(PC61BM),and polymethylmethacrylate(PMMA) were fabricated with and without using 1,8-dibromooctane(DBO) as solvent additive.The role of PMMA was to enable the formation of the smooth and continuous thin films spun from the solution onto the conducting substrate.In addition,the good stability of the PMMA against the heat,oxygen and water attacks was useful for achieving the long lifetime of organic solar cells.The LDP-PCPDTBT and PC61BM phases in the PMMA matrix were amorphous and crystalline,respectively,regardless of the additive processing.The crystalline aggregation of the LDP-PCPDTBT was hampered by the PC61BM molecules,though the additive processing was able to promote the degree of crystallinity of the LDP-PCPDTBT.However,with the additive processing the phase separation of the LDP-PCPDTBT and PC61BM components in the PMMA matrix was optimized,leading to the improved electron-transporting property and thereby an increase of 32.4% in the power conversion efficiency of solar cell,compared to without the additive processing.The current research indicates that the low polymerization degree alternating copolymers can be recycled as efficient electron donors in association with PMMA,helpful for reducing the material cost of organic solar cells.