Device Characteristics of GaInSb/AlGaSb Quantum Well Lasers Monolithically Grown on GaAs Substrates by Using an Interfacial Misfit Array

Abstract

We report the device characteristics of GaInSb/AlGaSb quantum well (QW) lasers monolithically grown on GaAs substrates by using an interfacial misfit (IMF) array. The IMF array localized at the GaSb/GaAs interface can accommodate the 7.8% lattice mismatch between GaAs substrates and GaSb buffer layers, resulting in the formation of a GaSb buffer with a very low defect density on GaAs substrates. Top-top and top-bottom metal contact methods are applied to the Ga0.9In0.1Sb/GaSb QW edge-emitting lasers monolithically grown on GaAs substrates for characterizing current–voltage (I–V) and output power–current (L–I) curves. The potential drop at the IMF array of ~0.7 V is elucidated by comparing I–V characteristics with these two contact methods. L–I characteristics and electroluminescence spectra shows room-temperature lasing at 1.83 μm from a 1.25-mm-long top-top contact device containing six-layer Ga0.9In0.1Sb QWs with a threshold current density (J th) of 860 kA/cm2. This IMF technique will enable a wide range of lasing wavelengths from near- to mid-wavelength infrared regimes on a GaAs platform.