Material Absorbance and Defect Impact on a Simplified Organic Solar Cell Structure using Graphene Oxide as a Dual Layer

Abstract

The rapid rise in global energy consumption has led to an increase in environmental concerns and economic challenges associated with conventional fossil fuels. As a result, green energy technologies, particularly solar cells, have attracted significant research attention. However, traditional solar cells often utilize toxic or costly materials, prompting the need for eco-friendly alternatives. Organic solar cells (OSCs), renowned for their low cost, flexibility, and eco-friendly nature, face limitations in terms of output and stability. This research proposes a simplified OSC structure featuring an organic polymer as the active layer, graphene oxide (GO) as a dual interfacial buffer layer, and indium-doped tin oxide (ITO) as a transparent conductor, with a nanoscale design. A notable consideration is the use of a gold strip as a back contact to enhance transparency and reduce material usage. The proposed model improves upon an earlier studied model with its dual-graphene approach by simplifying the structure in terms of processing and analysis, offering excellent optical properties that align with the material PTB7:PC71BM. The proposed model was analyzed using continuity and Poisson’s equations with the drift-diffusion method, employing the Solar Cell Capacitance Simulator (SCAPS-1D) solar cell analytical tool. This structure exhibits excellent photoelectronic properties, with output power conversion efficiency (PCE or n) of 20.03% and a fill factor (FF) of 77.13%. The proposed model possesses characteristics of stability, flexibility, and transparency, making it suitable for use at the application level. Performance analysis indicates enhanced photovoltaic parameters, including open-circuit voltage (Voc), short-circuit current density (Jsc), FF, and PCE, positioning this design as a promising step toward practical and sustainable OSC technology. © The Minerals, Metals & Materials Society 2026.