Current Applied Physics, Vol.16, No.3, 340-347, 2016
Investigation of the doping and Stark effects on the band structure and optical absorption of 1.55 mu m GaNAsBi/GaAs MQWs
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 mu m. 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 L-b = 12 nm. This transition energy shows a red shift when the doped DQWs are coupled (L-b = 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 undoped 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. (C) 2015 Elsevier B.V. All rights reserved.