III-V semiconductor materials are expensive and increasingly rare. Their replacement as the go-to material for lasers is inevitable. CEA-Leti researchers were part of an international team* that recently published a notable advance in Nature Photonics. They developed an optically-pumped IV-IV semiconductor device capable of producing a 2.5 micron laser beam with an ultra-low threshold at temperatures of 100 K.
The device was made by depositing germanium and then germanium-tin onto a silicon substrate. The resulting disk was then encapsulated in silicon nitride and voltage was applied to introduce mechanical strain before transferring the disk to aluminum pillars for heat dissipation. At this stage, the device is a laboratory prototype. However, it does confirm that lasers can be made without III-V materials.
*STMicroelectronics, C2N-CNRS, Forschung Zentrum Juelich