Assessing the nature of the distribution of localised states in bulk GaAsBi
Autor: | Robert D. Richards, John P. R. David, Phoebe Pearce, N. P. Hylton, Diego Alonso-Álvarez, Alexander Mellor, Nicholas J. Ekins-Daukes, Yukihiro Harada, T. Wilson |
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Rok vydání: | 2018 |
Předmět: |
Materials science
Photoluminescence Band gap near-infrared spectroscopy SEMICONDUCTOR ALLOY GAAS1-XBIX BAND-GAP lcsh:Medicine 02 engineering and technology 01 natural sciences Article Condensed Matter::Materials Science MOLECULAR-BEAM EPITAXY DEPENDENCE 0103 physical sciences HETEROSTRUCTURES Energy level lcsh:Science Spectroscopy LATTICES 010302 applied physics Multidisciplinary Science & Technology Condensed matter physics lcsh:R Heterojunction 021001 nanoscience & nanotechnology Crystallographic defect Multidisciplinary Sciences electronic devices Science & Technology - Other Topics GROWTH lcsh:Q PHOTOLUMINESCENCE 0210 nano-technology Luminescence Excitation |
Zdroj: | Scientific Reports Wilson, T, Hylton, N P, Harada, Y, Pearce, P, Alonso-Álvarez, D, Mellor, A, Richards, R D, David, J P R & Ekins-Daukes, N J 2018, ' Assessing the Nature of the Distribution of Localised States in Bulk GaAsBi ', Scientific Reports, vol. 8, no. 1, 6457, pp. 1-10 . https://doi.org/10.1038/s41598-018-24696-2 Scientific Reports, Vol 8, Iss 1, Pp 1-10 (2018) |
ISSN: | 2045-2322 |
Popis: | A comprehensive assessment of the nature of the distribution of sub band-gap energy states in bulk GaAsBi is presented using power and temperature dependent photoluminescence spectroscopy. The observation of a characteristic red-blue-red shift in the peak luminescence energy indicates the presence of short-range alloy disorder in the material. A decrease in the carrier localisation energy demonstrates the strong excitation power dependence of localised state behaviour and is attributed to the filling of energy states furthest from the valence band edge. Analysis of the photoluminescence lineshape at low temperature presents strong evidence for a Gaussian distribution of localised states that extends from the valence band edge. Furthermore, a rate model is employed to understand the non-uniform thermal quenching of the photoluminescence and indicates the presence of two Gaussian-like distributions making up the density of localised states. These components are attributed to the presence of microscopic fluctuations in Bi content, due to short-range alloy disorder across the GaAsBi layer, and the formation of Bi related point defects, resulting from low temperature growth. |
Databáze: | OpenAIRE |
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