1.54 µm GaSb/AlGaSb multi-quantum-well monolithic laser at 77 K grown on miscut Si substrate using interfacial misfit arrays

Abstract

A GaSb quantum-well (QW) laser diode grown monolithically on a 5° miscut Si (001) substrate is presented. The III-Sb epi-structure is grown monolithically on the miscut Si substrate via a thin (50 nm) AlSb nucleation layer. The 13% lattice mismatch between AlSb and Si is accommodated by a self-assembled, 2D array of interfacial misfit dislocations (IMF). The 5° miscut geometry enables simultaneous IMF formation and anti-phase domain suppression. The 1 mm × 100 µm GaSb QW laser diode operates under pulsed conditions at 77 K with a threshold current density of 2 kA/cm2 and a maximum peak power of ∼20 mW. Furthermore, the device is characterised by a 9.1 Ω forward resistance and a leakage current density of 0.7 A/cm2 at −5 V.