Numerical simulation of electrically-pumped overgrown III-V microwire lasers on silicon

Electrically-pumped III-V lasers on Si by aspect ratio trapping (ART) techniques have been a promising candidate for Si-based light sources . Although the lasers based on the ART approach enable large-scale integration and are compatible with complementary metal-oxide semiconductor processes, the sub-micron size laser structure suffers from severe metal absorption loss and heat accumulation. In this paper, we propose a novel Si-based III-V multi-quantum well laser by ART methods. The overgrowth of III-V microwires is adopted, with additional {110} quantum wells (QWs) generated during epitaxy . Through numerical simulation, the mode loss of the overgrowth structure is reduced from 3.59 dB/cm to 0.96 dB/cm, the threshold current is decreased by 42.5% and the output power is increased by 91.7% under pulsed conditions. Due to the growth of QWs on {110} planes, the injection efficiency of the device increases, leading to an improvement of performance. The effects of temperature and cavity length on the lasing characteristics of the device under continuous wave (CW) conditions are also analyzed that the proposed structure can realize CW lasing at room temperature. Moreover, the device deterioration caused by growth defects is discussed, which can be improved by high reflection coating. The suggested Si-based overgrowth III-V microwire laser has great potential to integrate high-density electrically-pumped light sources for silicon photonics . • We present a Si-based overgrown III-V microwire structure by aspect ratio trapping methods. • The threshold is reduced by 42.5% and the power is increased by 91.7% for the simulated new laser. • The proposed 1.5 μm electrically-pumped laser enables CW lasing at RT based on numerical results.