Abstract
The absence of bandgap bowing in the common-anion II-VI semiconductor ternary alloys is investigated. As examples, we consider the C d1 - x Z nx T e and C d1 - x Z nx S e alloys. The sp3s* tight-binding method with the inclusion of spin-orbit interactions is employed to calculate the alloy's band structure and its corresponding constituents' charge states (ionicities) as a function of composition. The variation is found to be nearly linear. The vanishingly small valence-band offset (VBO ≃ 0) in common-anion compounds would yield a linear scaling of bandgap energy with composition, especially as the conduction-band edge state being a singlet state with spherical symmetry. Furthermore, the two cation atoms (Cd and Zn) are found not to compete in changing their charge states as the composition is varied. The absence of such competition is believed to be the main reason for the absence of bowing. The theoretical results are compared to the available experimental data and found to be in good agreement. Crown
Original language | English |
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Pages (from-to) | 340-344 |
Number of pages | 5 |
Journal | Journal of Alloys and Compounds |
Volume | 481 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - Jul 29 2009 |
Keywords
- Electronic structures
- II-VI semiconductors
- Photoluminescence
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry