Grafted AlGaAs/GeSn Optical Pumping Laser Operating up to 130 K

TL;DR

This paper demonstrates a novel grafting technique to create AlGaAs/GeSn lasers that operate up to 130 K, showing promise for future room-temperature electrically injected GeSn lasers.

Contribution

It introduces a semiconductor grafting method to improve GeSn laser performance, overcoming limitations of conventional epitaxy and wafer bonding.

Findings

Lasing threshold of 11.06 mW at 77 K

Maximum lasing temperature of 130 K

Enhanced charge and optical confinement

Abstract

Group IV GeSn double-heterostructure (DHS) lasers offer unique advantages of a direct bandgap and CMOS compatibility. However, further improvements in laser performance have been bottlenecked by limited junction properties of GeSn through conventional epitaxy and wafer bonding. This work leverages semiconductor grafting to synthesize and characterize optically pumped ridge edge-emitting lasers (EELs) with an AlGaAs nanomembrane (NM) transfer-printed onto an epitaxially grown GeSn substrate, interfaced by an ultrathin Al2O3 layer. The grafted AlGaAs/GeSn DHS lasers show a lasing threshold of 11.06 mW at 77 K and a maximum lasing temperature of 130 K. These results highlight the potential of the grafting technique for enhancing charge carrier and optical field confinements, paving the way for room-temperature electrically injected GeSn lasers.