High-quality GeSn grown in foundry mode via chemical vapor deposition enabling lasing up to 235 K

Using a commercial chemical vapor deposition reactor operated in foundry mode, we rapidly developed high-quality, high-Sn-content GeSn growth recipes within just a few months from the initial trials. A recently discovered growth strategy—spontaneous-relaxation-enhanced (SRE) Sn incorporation—was employed to produce thick, low-defect GeSn layers. We conducted a comprehensive study of GeSn alloys with Sn compositions ranging from 3.1% to 18.2%. All samples exhibited strong room-temperature photoluminescence, confirming excellent material quality. For higher-Sn compositions, optically pumped lasing was achieved at wavelengths beyond 3.3 μm over a temperature range of 77–235 K, with a threshold power density of 338 kW/cm2 at 77 K. The demonstrated combination of foundry-mode operation and SRE-based growth offers a robust, scalable route for rapid GeSn material development, facilitating technology transfer to commercial foundries and accelerating progress toward GeSn-based photonic integration.