Study of [formula omitted]-Ga[formula omitted]O[formula omitted](001)/sapphire (a-plane) heterostructure in wide bandgap solar-blind deep-ultraviolet photodetector.

Gallium oxide ( Ga 2 O 3 ) with ultra-wide band gap and high radiation resistance have great potential in solar-blind ultraviolet (UV) photodetectors, but its development is limited by expensive Ga 2 O 3 substrate materials. Sapphire substrate, due to its high hardness, mature production process and low cost, has become one of the most favorable substrate materials for optoelectronic devices. So, Ga 2 O 3 -based optoelectronic devices on sapphire substrates hold significant commercial value. In this work, using first-principles density functional theory (DFT) calculations, we investigate the influence of interfacial oxygen concentration on the β - Ga 2 O 3 (001)/sapphire(11 2 ̄ 0) heterostructure. The results show that the bonding strength between O-terminated and Al-terminated interfaces is strong, indicating favorable thermodynamic stability of this heterostructure. Furthermore, we discover that the metal-O-metal bonding configuration at the interface effectively reduces the number of interfacial defects, increase the built-in electric field strength within the heterostructure, and improves the deposition quality of the β - Ga 2 O 3 film. This work holds significant implications for the research on β - Ga 2 O 3 solar-blind UV photodetectors based on sapphire substrates. • The β -Ga2O3(001)/sapphire(11 2 ̄ 0) interface models with four heterostructures were investigated. • The oxygen concentration at the interface affects the interface interactions and the structural stability. • Al model has fewer interface defects and the highest thermodynamic stability. • The β -Ga2O3(001)/sapphire(11 2 ̄ 0) heterostructure still shows strong optical absorption capacity in the deep ultraviolet region. • This theoretical research is valuable for the growth of high-quality β -Ga2O3 thin films on sapphire substrates experimentally. [ABSTRACT FROM AUTHOR]