Transfer printing of fully formed thin-film microscale GaAs lasers on silicon with a thermally conductive interface material

High performance semiconductor lasers on silicon are critical elements of next generation photonic integrated circuits. Transfer printing methods provide promising paths to achieve hybrid integration of III-V devices on Si platforms. This paper presents materials and procedures for epitaxially releasing thin-film microscale GaAs based lasers after their full fabrication on GaAs native substrates, and for subsequently transfer printing arrays of them onto Si wafers. An indium-silver based alloy serves as a thermally conductive bonding interface between the lasers and the Si, for enhanced performance. Numerical calculations provide comparative insights into thermal properties for devices with metallic, organic and semiconductor interfaces. Under current injection, the first of these three interfaces provides, by far, the lowest operating temperatures. Such devices exhibit continuous-wave lasing in the near-infrared range under electrical pumping, with performance comparable to unreleased devices on their native substrates. Fully formed thin-film microscale GaAs based lasers are integrated onto silicon substrates using a transfer printing method. An indium-silver alloy based adhesive layer serves as a thermally conductive interface. Experimental and numerical results demonstrate enhanced lasing performance due to advanced thermal management. The device integration strategies provide routes to on-chip light sources for silicon photonics.