Magneto-optical determination of the carrier lifetime in coherent Ge(1-x)Sn(x)/Ge heterostructures
- Resource Type
- Working Paper
- Authors
- Vitiello, Elisa; Rossi, Simone; Broderick, Christopher A.; Gravina, Giorgio; Balocchi, Andrea; Marie, Xavier; O'Reilly, Eoin P.; Myronov, Maksym; Pezzoli, Fabio
- Source
- Phys. Rev. Applied 14, 064068 (2020)
- Subject
- Physics - Optics
Condensed Matter - Mesoscale and Nanoscale Physics
Physics - Applied Physics
- Language
We present a magneto-optical study of the carrier dynamics in compressively strained Ge(1-x)Sn(x) films having Sn compositions up to 10% epitaxially grown on blanket Ge on Si (001) virtual substrates. We leverage the Hanle effect under steady-state excitation to study the spin-dependent optical transitions in presence of an external magnetic field. This allowed us to obtain direct access to the dynamics of the optically-induced carrier population. Our approach singled out that at cryogenic temperatures the effective lifetime of the photogenerated carriers in coherent Ge(1-x)Sn(x) occurs in the sub-ns time scale. Supported by a model estimate of the radiative lifetime, our measurements indicate that carrier recombination is dominated by non-radiative processes. Our results thus provide central information to advance the fundamental understanding of carrier kinetics in this novel direct-gap group-IV material system. Such knowledge can be a stepping stone in the quest for the implementation of Ge(1-x)Sn(x)-based functional devices.