Synthesis and Properties of Copolymers Composed of Arylenevinylene and Phenothiazine for Organic Solar Cells
作者:Ji-Hoon Kim、Dongbo Mi、In-Nam Kang、Won Suk Shin、Sung Cheol Yoon、Sang-Jin Moon、Changjin Lee、Jin-Kyun Lee、Do-Hoon Hwang
DOI:10.1166/jnn.2011.4505
日期:2011.7.1
A series of new organic semiconducting copolymers composed of (2E,2'E)-3,3'-[2,5-bis(octyloxy)-1,4-phenylene]-bis[2-(thiophen-2-yl)acrylonitrile]}(OPTAN) and 10(2'-ethylhexylphenothiazine) (PTZ) monomers, (the copolymers are hereafter referred to as poly(OPTAN-co-PTZ)s), were synthesized by using Suzuki coupling polymerization in which the monomer ratios were controlled. An increase in the OPTAN content shifted the peak and onset absorption of the copolymers to the longer wavelength regions, which resulted in a decrease in the band gap energy. The maximum UV absorption of the polymer films was in the range 523–540 nm and the optical band gap energies were in the range 1.90–1.87 eV. Energy levels of the highest occupied molecular orbital (HOMO) of the polymers were determined by cyclic voltammetry (CV). The HOMO energy level of the copolymers was between −5.07 and −5.12 eV. Photovoltaic devices were fabricated by using the copolymers as the p-type donor and C60-PCBM or C70-PCBM as the electron acceptors. The device with poly(50OPTAN-alt-50PTZ) and C70-PCBM showed the best performance among the fabricated devices; the open circuit voltage, short circuit current, fill factor, and maximum power conversion efficiency of this device were 0.79 V, 5.25 mA/cm2, 0.30, and 1.25%, respectively.
一系列由(2E,2'E)-3,3'-[2,5-二辛氧基-1,4-苯基]-双[2-(噻吩-2-基)丙烯腈]}(OPTAN)和10(2'-乙基己基苯噻嗪)(PTZ)单体组成的新型有机半导体共聚物(以下称为聚(OPTAN-co-PTZ))通过铃木偶联聚合反应合成,单体比例得到控制。OPTAN含量的增加使共聚物的吸收峰及起始吸收向长波长区域移动,从而导致带隙能量的降低。聚合物薄膜的最大紫外吸收在523–540 nm范围内,光学带隙能量在1.90–1.87 eV范围内。聚合物的最高占据分子轨道(HOMO)能量级通过循环伏安法(CV)确定。共聚物的HOMO能量级介于−5.07和−5.12 eV之间。利用共聚物作为p型供体,C60-PCBM或C70-PCBM作为电子受体,制造了光伏器件。聚(50OPTAN-alt-50PTZ)和C70-PCBM的器件在所制造的器件中表现最佳;该器件的开路电压、短路电流、填充因子和最大功率转换效率分别为0.79 V、5.25 mA/cm²、0.30和1.25%。