Monolithic III‐V Nanolasers on SOI With Deterministic Photon‐Carrier Colocalization

How to confine carriers deterministically and precisely at the nanophotonic cavity mode maximum is key to the fabrication of efficient III‐V nanolasers. Conventional blanket epitaxial quantum‐wells (QWs) offer weak horizontal carrier confinement and suffer from high nonradiative recombination at fabrication‐created interfaces. Self‐assembled single quantum‐dot (QD) offers excellent carrier confinement but its random location hinders large‐scale device fabrication. We demonstrate a novel approach based on selective lateral heteroepitaxy (SLH) on silicon‐on‐insulator (SOI). The process creates InP membranes embedded with vertically‐oriented InGaAs QWs that offer excellent horizontal carrier confinement. The QWs are precisely positioned relative to the pre‐fabricated growth template and therefore can be deterministically placed exactly at the optical mode maximum of the subsequently fabricated nanophotonic cavity. The approach achieves extremely large overlap between photons and carriers, resulting in highly efficient III‐V nanolasers coplanarly integrated with the silicon waveguide layer. The optically pumped nanolasers exhibit record‐low threshold of around 57 nW at room temperature, very high spontaneous emission factor (β) of 0.96, and stable continuous‐wave operation beyond 100°C. Our approach provides a compelling strategy for the development of efficient nanolasers that can be seamlessly integrated with silicon photonics platforms at large scale.