Investigation on crystal structures, optical properties, and band structure calculations of In2-xMxTeO6 (M = Ga, Bi, La)
| Autor: | Thanundon Kongnok, Theeranun Siritanon, Sirichok Jungthawan, Pinit Kidkhunthod, Arreerat Jiamprasertboon, Narong Chanlek |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Photoluminescence
Band gap Chemistry Mechanical Engineering Metals and Alloys 02 engineering and technology Crystal structure 021001 nanoscience & nanotechnology 01 natural sciences XANES Semimetal Bond length Crystallography Molecular geometry Mechanics of Materials 0103 physical sciences Materials Chemistry 010306 general physics 0210 nano-technology Electronic band structure |
| Zdroj: | Journal of Alloys and Compounds. 702:601-610 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2017.01.227 |
| Popis: | The study of structure, optical properties, and band structure of M substituted-In 2 TeO 6 (M = Ga 3+ , Bi 3+ , and La 3+ ) is presented. Solubility limit of each cation is different varying from 10% for La 3+ to 20% for Ga 3+ and 25% for Bi 3+ . Both XANES and XPS confirm the oxidation states of Bi 3+ and Te 6+ . Crystallographic data of bond lengths and bond angles suggest no significant distortion of M-O 6 octahedra for all samples; however, the stereoactive 6s 2 lone-pair electrons in Bi cause In/Bi cation in In/Bi O 6 to shift toward one edge of the octahedra. The band structure calculation was useful to clarify that the fundamental band gap energies of all series originate from the direct allowed transition. Interestingly, Bi greatly influences the conduction band dispersion and Bi 6s state additionally contributes at the valence band maximum, while the valence band of other M-doped and un-doped samples are mainly O 2p and In 4d in character. All compounds similarly exhibit photoluminescence properties. The strong PL peak mainly originated from the near band edge transition and the broad peak from Te 6+ O charge transfer are observed in all samples. |
| Databáze: | OpenAIRE |
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