Analytical modeling of temperature and power dependent photoluminescence (PL) spectra of InAs/GaAs quantum dots

Abstract

In order to theoretically analyze the Photoluminescence (PL) spectra and its dependence on temperature and power, we have calculated the electronic band structure of self-assembled InAs/GaAs Quantum Dots (QDs) with a temperature dependent 8 band k·p Hamiltonian by including the effects of strain. The transition energies for the ground state and the first excited state are calculated using a mathematical model, which takes into account the effect of both homogeneous and inhomogeneous broadening, caused due to carrier scattering processes and QD size variation, respectively. Our proposed analytical model describes the origin of bimodal peak in the PL spectra and its correlation with the transition energies for different temperatures by considering the temperature induced intrinsic carrier concentration and carrier relaxation time. The applicability of the derived expression is validated using the experimental data of single layer InAs/GaAs QDs grown using Stranski-Krastanov growth mode. In addition to this, the simplicity of the model and its various useful aspects including computation of temperature dependent electronic band profiles and complete PL spectra make it a potential tool to study the optoelectronic properties of QD heterostructures.