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作者: Ya-Nan W (Ya-Nan, Wang)1, Yin-Hua Z (Yin-Hua, Zhou)1, Yue X (Yue, Xu)2, Xiao-Bo S (Xiao-Bo, Sun)3, Wei-Cai W (Wei-Cai, Wu)1, Wen-Jing T (Wen-Jing, Tian)1, Yun-Qi L (Yun-Qi, Liu)3

来源出版物: CHINESE PHYSICS B    卷: 17    期: 4    页: 1448-1453    出版年: APR 2008

摘要: The films of two x-shape oligo(thiophene)s, 3, 4-dibithienyl-2, 5-dithienylthiophene (7T) and 2, 5-dibithienyl-3, 4-ditrithienylthiophene (11T), which are prepared by vacuum evaporation, have been investigated as novel electron donor layers in two-layer photovoltaic cells. UV-Vis absorptions show red-shifted and broadened absorptions of the vacuum-evaporated films as compared with those of the corresponding solutions and spin-coating films, which is beneficial for photovoltaic properties. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements show that the vacuum-evaporated films are almost amorphous. Two-layer photovoltaic cells have been realized by the thermal evaporation of 7T and I IT as donors and N, N'-bis(1-ethylpropyl)-3, 4:9,10-perylene bis(tetracarboxyl diimide) (EP-PTC) as an acceptor. An energy conversion efficiency (ECE) of 0.18% of the cell based on 7T with an irradiation of white light at 100 mw/cm(2) has been demonstrated by the measurements of current (I)- voltage (V) curves of the cells to be higher than the ECE of the reference system based on donor dihexylterthienyl (H3T) that is linear and without alpha, beta linkage.