Theoretical analyses of the carrier localization effect on the photoluminescence of In-rich InGaAs layer grown on InP

Abstract

The free buffer InGaAs/InP structure has been elaborated by Metal Organic Vapor Phase Epitaxy (MOVPE). High indium content is chosen to reduce the bandgap energy of the ternary material with direct bandgap to be promoted for Infrared optoelectronic devices. In this work, the temperature dependent photoluminescence (TDPL) analysis of In-rich InxGa1����� xAs (x = 0.65: S1, x = 0.661: S2, and x = 0.667 S3) samples is of the central focus. The S-shaped behavior recorded at low temperature range in the III-V ternary is quantitatively studied herein by Localized State Ensemble (LSE) model. A comparison between the semi-empirical evolution of luminescence versus temperature and our numerical simulation proves the adequacy of computational details, used in LSE model, in well reproducing the S-shape feature. The numerical simulation well matched with PL spectra proving that the localization phenomenon is stronger when increasing the Indium mole fraction. The clustering effect in In-rich structure seems to be beneficial for enhancing the carrier localization within InxGa1����� xAs by localizing carriers from away extended defects that behave probably as non-radiative centers. This is indicative of the utmost importance of localization phenomenon in trapping carriers within localized states instead of dislocations and defects, owing to clustering of indium atoms.