Enhanced numerical design of two-barrier infrared detectors with III–V compounds heterostructures considering the influence of lattice strain and misfit dislocations on the band gap

Abstract

The goal of this work is the design of efficient infrared radiation detectors based on InAsSb compounds with two energy barriers around the absorber region. Two types of two-barrier detectors that work in the 3-5.5 μm wavelength range at 230 K is designed. Using our computer program to iteratively solve the Poisson equation, the spatial distribution of energy band edges in III-V heterostructures was calculated The influence of lattice stress, bending of the structure and doping on the energy shift of the edge of the bands is considered. Lattice strain is the cause of the formation of the misfit dislocations at the boundaries of the individual layers of the heterostructure. These dislocations partially relax the resulting stress and affect the lattice deformation in individual layers. From the minimum elastic energy condition, the density of these dislocations is determined. It has been shown that the band offset can be eliminated in the areas of both barriers in the designed two-barrier detectors.

Ultrafast infrared spectroscopy of InAs/GaSb and InAs/InAsSb type-II superlattices

“…InAs/GaSb SLs are more explored than InAs/InAsSb in terms of their physical properties, but it has been reported that introducing gallium atoms to the structure lowers the structural quality of the material through native point defects and has a negative impact on working parameters of the device 25 . To balance the gallium-induced defects it is crucial to maintain a balanced strain throughout the whole growth process to avoid "relieving" the strain by the SL through formation of the defects 26 .…”