Near band edge anisotropic optical transitions in wide band gap semiconductor Cu2ZnSiS4
| Autor: | S. Levcenco, Dumitru Dumcenco, V. Tezlevan, Ying-Sheng Huang, Ernest Arushanov, C.H. Du, Kwong-Kau Tiong |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 108:073508 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.3490219 |
| Popis: | In this study, anisotropic near band edge transitions of Cu2ZnSiS4 single crystals grown by chemical vapor transport were characterized by using polarization-dependent absorption, piezoreflectance (PzR) and surface photovoltage (SPV) spectroscopy techniques at room temperature. The measurements were carried out on the as grown basal plane with the normal along [2 1 0] and the axis c parallel to the long edge of the crystal platelet. Analysis of absorption and SPV spectra reveal indirect allowed transitions for the absorption edge of Cu2ZnSiS4. The estimated values of indirect band gap are 2.97 eV and 3.07 eV, respectively, for E⊥c and E∥c polarization configurations. The polarization-dependent PzR and SPV spectra in the vicinity of the direct band gap of Cu2ZnSiS4 reveal features E⊥ex and E∥ex at around 3.32 eV and 3.41 eV for E⊥c and E∥c polarizations, respectively. Both features E⊥ex and E∥ex are associated with the interband excitonic transitions at point Γ and can be explained by crystal-field splitti... |
| Databáze: | OpenAIRE |
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