Two dimensional modeling of Cu2O heterojunction solar cells based-on β-Ga2O3 buffer

Despite the advantages of cuprous oxide (Cu2O) as a cheap, abundant, non-toxic, and sustainable photovoltaic material, defects and conduction band offset (CBO) at the Cu2O heterojunction interfaces are still the most challenges to achieve higher efficiencies. In this study, a Cu2O heterojunction solar cell based on a β-Ga2O3 buffer has been modeled and simulated using Silvaco TCAD. The model exactly matches the reported experimental results of open circuit voltage (VOC) and short current density (JSC) characteristics and well reproduces the fill factor (FF) and efficiency, η, of a fabricated solar cell within ±2% tolerance. By using the model, we explored a novel structure for higher efficiency solar cell by adding an interface and a defective layer. It was found that the associated defects and traps to each layer significantly influence the electrical and optical characteristics of the solar cell performance. The model shows an external quantum efficiency (EQE) more than 0.6, an FF greater than 68% and an η about 5.44% under the AM1.5 illuminations. Furthermore, the model shows that it can be used generously to investigate the parameters of the Cu2O-based solar cells with different buffers prior to fabricate.