Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DS: Fachverband Dünne Schichten

DS 21: Optical Analysis of Thin Films

DS 21.3: Vortrag

Freitag, 13. März 2026, 10:00–10:15, REC/C213

Pressure-dependent photoluminescence and Raman spectra of GeSn alloys — •Stefan Zollner¹, Sonam Yadav¹, Meghan A. Worrell¹, Preston T. Webster², Rigo A. Carrasco², and Perry C. Grant³ — ¹New Mexico State University, Las Cruces, NM, USA — ²AFRL Space Vehicles Directorate, Albuquerque, NM, USA — ³Arktonics LLC, Fayetteville, AR, USA

Optical spectra of Ge_1−xSn_x alloys (x<10%) grown on Si by chemical vapor deposition were acquired in a gas-membrane diamond anvil cell at pressures up to 10 GPa. The Si substrate contracts hydrostatically under pressure and imposes a biaxial stress on the thin epitaxial layer. The tetragonal distortion of the layer can be calculated from the bulk modulus of the substrate and the elastic constants of the layer. Room temperature Raman spectra of bulk Ge with 532 nm excitation show a parabolic blueshift from 300 cm⁻¹ at atmospheric pressure to 335 cm⁻¹ at 10 GPa. The blueshift due to pressure is linear and slightly larger for Ge on Si. We also acquired photoluminescence spectra of Ge_1−xSn_x alloys as a function of temperature and pressure. We observe a blueshift of the infrared Ge_1−xSn_x emission at 10 K of 46 meV/GPa which quenches at 0.6 GPa. For MWIR III/V multiple quantum wells, the blueshift is larger at 77 meV/GPa and the emission quenches at 1.3 GPa.

Keywords: germanium-tin alloys; high-pressure; Raman; photoluminescence; semiconductors