Ab-initio calculation of band alignments for opto-electronic simulations

Jan Oliver Oelerich,Stephan W Koch,Kerstin Volz,Maria J Weseloh

doi:10.1063/1.5087756

Abstract

A modified core-to-valence band maximum approach is applied to calculate band offsets of strained III/V semiconductor hetero junctions. The method is used for the analysis of (In,Ga)As/GaAs/Ga(As,Sb) multi-quantum well structures. The obtained offsets and the resulting bandstructure are used as input for the microscopic calculation of photoluminescence spectra yielding very good agreement with recent experimental results.

Highlights

Semiconductor hetero structures are the basic building blocks of many opto-electronic devices, such as solar cells, semiconductor sensors, or laser diodes
One fundamental requirement for the reliable prediction of the opto-electronic semiconductor hetero structure properties is a detailed knowledge of the electronic band structure throughout the device
The infinite band structures of the reference bulk systems are modified to take into account lattice strain imposed by the substrate, and quantum confinement arising from finite layer thicknesses

Summary

INTRODUCTION

Semiconductor hetero structures are the basic building blocks of many opto-electronic devices, such as solar cells, semiconductor sensors, or laser diodes. The critical parameter required to connect the band structures at an interface is the relative energy offset of their valence band maxima (VBMs), the valence band offset (VBO).. The critical parameter required to connect the band structures at an interface is the relative energy offset of their valence band maxima (VBMs), the valence band offset (VBO).3 It determines both, transport across the interface as well as quantum confinement of the layers, making it one of the most important parameters for the design of hetero structures.

THE MODIFIED CORE-TO-VBM APPROACH

Band offsets

Photoluminescence

CONCLUSION