The electronic and optical properties of quaternary GaAs(1-x-y )N( x )Bi( y ) alloy lattice-matched to GaAs: a first-principles study

First-principles calculations based on density functional theory have been performed for the quaternary GaAs(1-x-y )N( x )Bi( y ) alloy lattice-matched to GaAs. Using the state-of-the-art computational method with the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, electronic, and optical properties were obtained, including band structures, density of states (DOSs), dielectric function, absorption coefficient, refractive index, energy loss function, and reflectivity. It is found that the lattice constant of GaAs(1-x-y )N( x )Bi( y ) alloy with y/x =1.718 can match to GaAs. With the incorporation of N and Bi into GaAs, the band gap of GaAs(1-x-y )N( x )Bi( y ) becomes small and remains direct. The calculated optical properties indicate that GaAs(1-x-y )N( x )Bi( y ) has higher optical efficiency as it has less energy loss than GaAs. In addition, it is also found that the electronic and optical properties of GaAs(1-x-y )N( x )Bi( y ) alloy can be further controlled by tuning the N and Bi compositions in this alloy. These results suggest promising applications of GaAs(1-x-y )N( x )Bi( y ) quaternary alloys in optoelectronic devices.