Intersubband absorption at 1.55μm in symmetrical AlInN/GaN/AlInN/GaN/AlInN quantum well structures

Abstract

This work provides a theoretical evaluation of the optical absorption associated with the intersuband in a symmetrical AlInN/GaN/AlInN/GaN/AlInN structure grown in a c-plane. The simulation process begins by solving the coupled Schrödinger-Poisson equations taking into account the effect of polarizations. Subsequently, the intersubband optical absorption coefficient derived from the density-matrix formalism is calculated. The effects of the variation of the indium composition in the central AlInN barrier and the employment of planar doping across the different layers in the AlInN/GaN/AlInN/GaN/AlInN structure on the intersubband absorption have been investigated. The analyzed results indicate that:(i) The intensity of the threshold of the absorption coefficient as well as its energetic position are affected by the indium composition and the ionization rate of the impurity. (ii) The adjustment of the indium composition and the planar doping allow the structure to achieve the desired transition that is $1.55\mu m$ (i.e.,0.80 eV). The outcome of this work provides new prospects for optical properties associated with intersubband transitions of indium III-nitride structures, highlighting their potential for application in communication.