Disentangling nonradiative recombination processes in Ge micro-crystals on Si substrates
- LNESS and Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, I-20125 Milano (Italy)
- School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT (United Kingdom)
- LNESS, Dipartimento di Fisica del Politecnico di Milano and IFN-CNR, Polo Territoriale di Como, Via Anzani 42, I-22100 Como (Italy)
- LNESS, Dipartimento di Fisica del Politecnico di Milano and IFN-CNR, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy)
We address nonradiative recombination pathways by leveraging surface passivation and dislocation management in μm-scale arrays of Ge crystals grown on deeply patterned Si substrates. The time decay photoluminescence (PL) at cryogenic temperatures discloses carrier lifetimes approaching 45 ns in band-gap engineered Ge micro-crystals. This investigation provides compelling information about the competitive interplay between the radiative band-edge transitions and the trapping of carriers by dislocations and free surfaces. Furthermore, an in-depth analysis of the temperature dependence of the PL, combined with capacitance data and finite difference time domain modeling, demonstrates the effectiveness of GeO{sub 2} in passivating the surface of Ge and thus in enhancing the room temperature PL emission.
- OSTI ID:
- 22590656
- Journal Information:
- Applied Physics Letters, Vol. 108, Issue 26; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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