GaAs-based strain-balanced GaNxAs1-x-yBiy type-I and -II multi-quantum wells for near-infrared photodetection range

Highlights: • Optoelectronic properties of strained GaNAsBi/GaAs quantum wells (QWs) were studied. • Strain balanced GaNAsBi/GaNAsBi QWs were investigated by zero-stress balance model. • Limits of thickness for each strained GaNAsBi layer were discussed. • Type-I and -II QWs based on these strain balanced heterostructures were explored. • Near-infrared applications based on the type-II QWs with "W" shape were proposed. Electronic band structure of t₂-GaN_x2As_1-x2-y2Bi_y2/t₁-GaN_x1As_1-x1-y1Bi_y1 strain-balanced quantum wells (QWs) elaborated on GaAs substrate was theoretically studied. Our study is based on the band anti-crossing model combined with the envelope function formalism. Using the zero stress balance model, the strain compensation criteria (N and Bi compositions, and thickness ratio ($t_1/t_2$) for the strain-balanced QWs is investigated. The critical thickness for each strained GaNAsBi layer is also discussed. Through the results, we found that the control of the compositions (x₁,y₁) and (x₂,y₂) for the tensile and compressive strained layers respectively, could modulate the band alignment of the strain-balanced QWs. The use of strain-balanced GaN_x2As_1-x2-y2Bi_y2/GaN_x1As_1-x1-y1Bi_y1type-II "W" QWs is quite promising candidate for GaAs-based near-infrared photodetection range as compared to strain-balanced type-I QWs counterparts.