Enhancing Organic Solar Cell Performance Using Novel Conjugated Compounds

This article deals with a series of six organic D-n-A molecules consisting of thiophene and carbazole. This series includes molecules with identical donor and acceptor groups, but different π-systems. We examined the effect of substituting thiophene (T) with phenylene (P), carbazole (C), fluorene (F) and anthracene (A) as π-systcms on the physical properties of these molecules. Using one-dimensional microelectronic and photonic structure analysis (AMPS-1D), we investigated and simulated the operational characteristics of orgnic heterojunction solar cells. These solar cells were constructed using the compound D1-B-Ed-B-D2-A as electron donor and [6], [6]-phenyl-C61-butyric acid methyl ester (PCBM) as electron acceptor. The performance of organic photovoltaic cells has shown significant improvements on various parameters, such as open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), power conversion efficiency (PCE), as well as series resistance (Rs) and shunt resistance (Rsh). In addition, devices based on P3-B-Ed-B-T3-A/PCBM and P3-B-Ed-B-T3-A/PCBM show power conversion efficiencies (PCE) of 8% and 9%, respectively. The introduction of a PEDOT layer between the indium-tin oxide (ITO) and the aluminum oxide layer significantly improved the performance of devices based on P3-B-Ed-B-T3-A/PCBM and P3-B-Ed-B-P3-A/PCBM, with PCEs of 14% and 15%, respectively.