Proposal and design of III-V/Si hybrid lasers with current injection across conductive wafer-bonded heterointerfaces

We propose three types of III-V/Si hybrid laser structures utilizing conductive wafer-bonded III-V/Si heterointerfaces. Our structures enable vertical current injection across the bonded heterinterfaces and therefore have advantages of lateral current confinement leading to higher quantum efficiencies and simpler fabrication without mesa etch or ion implantation in contrast to the previous lateral-current-injection III-V/Si hybrid lasers using SiO₂-mediated wafer bonding. As a preliminary demonstration, we have fabricated InAs/GaAs quantum dot lasers on Si substrates with current injection across direct-bonded GaAs/Si Ohmic heterointerfaces.