Optimization and Simulation of the photovoltaic properties of modified Donor-Acceptor Conjugated Oligomers for Organic Solar Cells

In this study, the analysis of microelectronic and photonic structure in one dimension program [AMPS-1D] has been successfully used to study organic solar cells. The program was used to optimize the performance of the organic solar cells based on (Carbazole-Methylthiophene), benzothiadiazole, Thiophene [(Cbz-Mth)-B-T]2 and [6, 6] -phenyl-C61-butyric acid methyl ester (PCBM). The cells considered, consist of Carbazole-Methylthiophene-Thiophene as electron donors, and benzothiadiazole, (6,6)-phenyl-c61-butyric acid methyl ester [PCBM] as electron acceptor. [(Cbz-Mth) -BT]2-PCBM] is used as photo active material, sandwiched between a transparent indium tin oxide (ITO) and an Al backside contact. The optoelectronic properties of these dyes were investigated by using the Density Functional Theory DFT/B3LYP/6-31G (d, p) method. We studied the influence of the variation of the thickness of the active layer, the temperature and the density of the effective states of the electrons and the holes in the conduction and valence bands respectively on the performance of the solar cells. The results were compared with the experimental data, it showed that the optimum thickness of the solar cell is about 120 nm, the maximum efficiency for the studied organic solar cell is about 9.458 % and the open circuit voltage decreases with temperature.