Thermal performance of GaInSb quantum well lasers for silicon photonics applications

TL;DR

This study investigates the thermal performance of GaInSb quantum well lasers compatible with silicon photonics, focusing on their temperature dependence and potential design improvements for integration on silicon.

Contribution

It provides new insights into the thermal behavior of GaInSb quantum well lasers on silicon and suggests design optimizations for better performance and integration.

Findings

Carrier leakage to X minima dominates temperature dependence.

Up to 43% of threshold current due to leakage at room temperature.

Design refinements can improve device performance.

Abstract

A key component for the realization of silicon-photonics are integrated lasers operating in the important communications band near 1.55 ${\mu}$m. One approach is through the use of GaSb-based alloys which may be grown directly on silicon. In this study, silicon-compatible strained Ga$_{0.8}$In$_{0.2}$Sb/Al$_{0.35}$Ga$_{0.65}$As$_{0.03}$Sb$_{0.97}$ composite quantum well (CQW) lasers grown on GaSb substrates emitting at 1.55 ${\mu}$m have been developed and investigated in terms of their thermal performance. Variable temperature and high-pressure techniques were used to investigate the influence of device design on performance. These measurements show that the temperature dependence of the devices is dominated by carrier leakage to the X minima of the Al$_{0.35}$Ga$_{0.65}$As$_{0.03}$Sb$_{0.97}$ barrier layers accounting for up to 43% of the threshold current at room temperature. Improvement in device performance may be possible through refinements in the CQW design, while carrier confinement may be improved by optimization of the barrier layer composition. This investigation provides valuable design insights for the monolithic integration of GaSb-based lasers on silicon.