Electronic Bands and Dielectric Functions of In0.5Tl0.5I Solid State Solution with Structural Defects
| Autor: | J. Piekarski, Bohdan Andriyevsky, A. I. Kashuba, I. V. Karpa, I. M. Kunyo, V. B. Stakhura, I. V. Semkiv, Michal Piasecki, Krzysztof Dorywalski, L. Andriyevska |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Condensed matter physics Solid-state physics 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Brillouin zone Condensed Matter::Materials Science Effective mass (solid-state physics) Atomic electron transition Vacancy defect 0103 physical sciences Materials Chemistry Density functional theory Electrical and Electronic Engineering 0210 nano-technology Anisotropy Electronic band structure |
| Zdroj: | Journal of Electronic Materials. 48:5586-5594 |
| ISSN: | 1543-186X 0361-5235 |
| DOI: | 10.1007/s11664-019-07404-2 |
| Popis: | We investigate an influence of the crystal structure imperfections on the electronic properties and dielectric functions of the In0.5Tl0.5I semiconductor in the frame of the density functional theory calculations. The tensor of electron effective mass $$ m^{*}_{ij} $$ for the InI, In0.5Tl0.5I and TlI crystals has been calculated for the valence and conduction bands at different K-points of the Brillouin zone. The dielectric functions e(hν) of the imperfect crystals based on In0.5Tl0.5I solid state solution with iodine vacancy and a thallium interstitial atom were calculated taking into consideration the inter-band and intra-band electron transitions. The studies of the imperfect crystals reveal increased low-frequency and stationary electron conductivity with anisotropy resulted from the anisotropy of the electron effective mass tensor. Our findings explain the origin of crucial changes in the band structure by formation of the donor half-occupied levels close to the unoccupied conduction bands due to the crystal structure defects, i.e., iodine vacancy or a thallium interstitial atom. It has been shown that in the case of real crystals, in particular metal-halides, the proper consideration of defects in quantum-chemical calculations results in a better matching with experimental data and, opposite to the perfect structure calculations, gives opportunities to explain the observed phenomena. |
| Databáze: | OpenAIRE |
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