Abstract
Ge-based spin-photodiodes have been employed to investigate the spectral dependence of optical spin orientation in germanium, in the range 400–1550 nm. We found the expected maximum in the spin polarization of photocarriers for excitation at the direct gap in (1550 nm) and a second sizable peak due to photogeneration in the valleys (530 nm). Data suggest distinct spin depolarization mechanisms for excitation at and , with shorter spin relaxation times whether the point is involved. These devices can be used as integrated photon-helicity detectors over a wide spectral range.
- Received 30 December 2013
- Revised 2 September 2014
DOI:https://doi.org/10.1103/PhysRevB.90.161304
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