Low Threshold Quantum Dot Lasers Directly Grown on Unpatterned Quasi-Nominal (001) Si

Abstract

We report electrically pumped, continuous-wave (cw) InAs/GaAs quantum dot (QD) lasers directly grown on quasi-nominal Si (001) substrates with offcut angle as small as 0.4°. No GaP, Ge buffer layers or substrate patterning is required. An anti-phase boundary free epitaxial GaAs film was grown by metal-organic chemical vapor deposition (MOCVD) with a low threading dislocation density of 3 × 107 cm-2. Room-temperature cw lasing at ∼1.3 μm has been achieved, with a minimum threshold current density of 34.6 A/cm2 per layer, a maximum operating temperature of 80 °C, and a maximum single facet output power of 52 mW. A comparison of various monolithic III-V hetero-epitaxy on Si solutions is presented. Direct growth on unpatterned quasi-nominal (001) Si may yield the best material quality at the lowest lifecycle cost.