Radiative Carrier Lifetime in Ge$_{1-x}$Sn$_x$ Mid-Infrared Emitters

• DOI: 10.48550/arxiv.2302.02467
• Publication Date: 2023-01-01
• Authors: Gérard Daligou; Anis Attiaoui; Simone Assali; Patrick Del Vecchio; Oussama Moutanabbir
• Keywords: Carrier lifetime

Ge$_{1-x}$Sn$_x$ semiconductors hold the premise for large-scale, monolithic mid-infrared photonics and optoelectronics. However, despite successful demonstration of several Ge$_{1-x}$Sn$_x$-based photodetectors emitters, key fundamental properties this material system are yet to be fully explored understood. In particular, little is known about role in controlling recombination mechanisms their consequences on carrier lifetime. Evaluating latter fact fraught with large uncertainties that exacerbated by difficulty investigate narrow bandgap semiconductors. To alleviate these limitations, herein we demonstrate radiative lifetime can obtained from straightforward excitation power- temperature- dependent photoluminescence measurements. end, a theoretical framework introduced simulate measured spectra combining band structure calculations k.p theory envelope function approximation (EFA) estimate absorption spontaneous emission. Based model, temperature-dependent emission Ge$_{0.83}$Sn$_{0.17}$ samples at biaxial compressive strain $-1.3\%$ was investigated. The simulated reproduce accurately data thereby enabling evaluation steady-state lifetimes, which found 3-22 ns range temperatures between 10 300 K an power 0.9 kW/cm$^2$. For lower 0.07 kW/cm$^2$, has value 1.9 4 K. demonstrated approach yielding simple will provide valuable inputs improve design modeling devices.