Thermal performance of GaInSb quantum well lasers for silicon photonics applications

Abstract

A key component for the realization of silicon-photonics are integrated lasers operating in the important communications band near 1.55 µm. One approach is through the use of GaSb-based alloys which may be grown directly on silicon. In this study, silicon-compatible strained Ga0.8In0.2Sb/Al0.35Ga0.65As0.03Sb0.97 composite quantum well (CQW) lasers grown on GaSb substrates emitting at 1.55 μm 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 Al0.35Ga0.65As0.03Sb0.97 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.

Improving the quality and properties of GaInSb crystal with Al doping

“…And the band gap can be increased from 0.18 eV (InSb) to 0.725 eV (GaSb) [4,5], and the cutoff wavelength can be adjusted from 1.7 μm (GaSb) to 7.3 μm (InSb) [6]. Therefore, GaInSb crystals can be more widely used in epitaxial substrate materials [7], quantum well lasers [8], high electron mobility transistors [9], thermoelectric materials [10,11], as well as infrared (IR) and near-infrared (NIR) devices [12][13][14][15] and other fields.…”