Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy
| Autor: | E. G. LeBlanc, Darius Kuciauskas, Katherine Zaunbrecher, Sandeep Sohal, Olanrewaju S. Ogedengbe, Pathiraja A. R. D. Jayathilaka, C. H. Swartz, Teresa M. Barnes, T. H. Myers, Bobby Logan Hancock, Pat Dippo, M. Edirisooriya |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Photoluminescence Materials science Physics and Astronomy (miscellaneous) business.industry Heterojunction 02 engineering and technology 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences Cadmium telluride photovoltaics 0103 physical sciences Optoelectronics Charge carrier Emission spectrum 0210 nano-technology business Recombination Molecular beam epitaxy |
| Zdroj: | Applied Physics Letters. 109:091904 |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/1.4961989 |
| Popis: | Heterostructures with CdTe and CdTe1-xSex (x ∼ 0.01) absorbers between two wider-band-gap Cd1-xMgxTe barriers (x ∼ 0.25–0.3) were grown by molecular beam epitaxy to study carrier generation and recombination in bulk materials with passivated interfaces. Using a combination of confocal photoluminescence (PL), time-resolved PL, and low-temperature PL emission spectroscopy, two extended defect types were identified and the impact of these defects on charge-carrier recombination was analyzed. The dominant defects identified by confocal PL were dislocations in samples grown on (211)B CdTe substrates and crystallographic twinning-related defects in samples on (100)-oriented InSb substrates. Low-temperature PL shows that twin-related defects have a zero-phonon energy of 1.460 eV and a Huang-Rhys factor of 1.50, while dislocation-dominated samples have a 1.473-eV zero-phonon energy and a Huang-Rhys factor of 1.22. The charge carrier diffusion length near both types of defects is ∼6 μm, suggesting that recombinati... |
| Databáze: | OpenAIRE |
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