Two-dimensional type-II BlueP/GaN heterostructure for solar cells: A first-principles study

The geometric structure, electronic and optical properties, power conversion efficiency (PCE) of the BlueP/GaN heterostructure and its response to biaxial strain and electric field are systematically studied based on firstprinciples calculations. The results show that all configurations are found to be semiconductors with indirect band gaps of 1.34, 1.79, 1.20 and 1.40 eV, respectively. The BlueP/GaN heterostructure possesses excellent carrier mobility. The electron mobility of AA' configuration is up to 3.329 m2 V-1 s-1, while the hole mobility can reach 1.707 m2 V-1 s-1. The visible light absorption intensity of the BlueP/GaN heterostructure can significantly improve compared with the corresponding monolayers. The maximum adsorption coefficient of AA configuration can attain to 1.01 x 105 cm-1 at the 422 nm visible light. Especially, the tunable band gap and type-II band alignment are achieved through biaxial strains and external electric fields. The BlueP/GaN heterostructure can achieve 24.13 % PCE at 4 % tension strain. External electric fields can more accurately modulate the band gap to dynamically control electronic properties of BlueP/GaN heterostructure. Hence, the results not only provide theoretical basis for sustainable energy application of BlueP/GaN heterostructure, but also provide motivation to experimentally explore BlueP/GaN heterostructure for harvesting green, abundant and clean solar energy.