Perspective: optically-pumped III-V quantum dot microcavity lasers via CMOS compatible patterned Si (001) substrates

Direct epitaxial growth III-V quantum dot (QD) structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photonic integration. However, epitaxial growth of III-V materials on Si encounters the following three major challenges: high density of threading dislocations, antiphase boundaries and thermal cracks, which significantly degrade the crystal quality and potential device performance. In this review, we will focus on some recent results related to InAs/GaAs quantum dot lasers on Si (001) substrates by III-V/IV hybrid epitaxial growth via (111)-faceted Si hollow structures. Moreover, by using the step-graded epitaxial growth process the emission wavelength of InAs QDs can be extended from O-band to C/L-band. High-performance InAs/GaAs QD microdisk lasers with sub-milliwatts threshold on Si (001) substrates are fabricated and characterized. The above results pave a promising path towards the on-chip lasers for optical interconnect applications.