Investigation of the doping and Stark effects on the band structure and optical absorption of 1.55 μm GaNAsBi/GaAs MQWs

•Doping effect on band structure of 1.55 μm GaNAsBi/GaAs MQWs is studied.•A red shift of the fundamental transition is shown due to the coupling and Stark effects.•Absorption coefficient of these MQWs increases with the rise of doping density.•Electric field dependence of the absorption coefficient is also investigated.•Well parameters are adjusted to obtain GaNAsBi-based MQWs operating at 1.55 μm.

We present a self-consistent calculation combined with the 16-band anticrossing model in order to investigate the electronic and optical properties of n-doped GaNAsBi/GaAs multiple-QWs operating at 1.55 μm. Optoelectronic features of these quantum structures seem advantageous for the design of photodetector devices. We have found that doping induces a blue shift of the fundamental transition energy for the uncoupled double-QWs with the barrier width Lb = 12 nm. This transition energy shows a red shift when the doped DQWs are coupled (Lb = 2 nm). An applied electric field favors further this shift. The coupling and Stark effects on the spatial distribution of confined electrons density are discussed. The absorption coefficient for the coupled 4 nm GaN.04As.89Bi.07/GaAs DQWs is enhanced compared to the un-doped or uncoupled DQWs. Finally, we have examined the dependence of the absorption magnitude on the doping density and electric field for different values of wells number.

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