Abstract
The urgent need for solar electricity production is critical for ensuring energy security and mitigating climate change. Achieving the optimal optical bandgap and effective carrier separation, essential for high-efficiency solar cells, remains a significant challenge when utilizing a single material. In this study, we design a BAs/GeC heterostructure using density functional theory. Our findings indicate that the BAs/GeC heterostructure exhibits direct bandgap semiconductor characteristics. Notably, the BAs/GeC heterostructure demonstrates excellent optical absorption within the infrared and visible light spectrum. Moreover, significant carrier spatial separation was suggested, facilitated by a Z-scheme pathway. Furthermore, applying biaxial strains revealed that the BAs/GeC heterostructure is unstable under compressive strain. However, the electronic and optical properties can be tuned using tensile biaxial strains. The calculated power conversion efficiency (PCE) of the BAs/GeC heterostructure is approximately 31%, as determined by the Scharber method. Hence, the combination of an appropriate bandgap, substantial carrier separation, and superior photoelectric conversion efficiency positions the BAs/GeC heterostructure as a promising candidate for high-efficiency solar cells.