Compound semiconductor alloys: From atomic-scale structure to bandgap bowing
- Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany)
Compound semiconductor alloys such as In{sub x}Ga{sub 1−x}As, GaAs{sub x}P{sub 1−x}, or CuIn{sub x}Ga{sub 1−x}Se{sub 2} are increasingly employed in numerous electronic, optoelectronic, and photonic devices due to the possibility of tuning their properties over a wide parameter range simply by adjusting the alloy composition. Interestingly, the material properties are also determined by the atomic-scale structure of the alloys on the subnanometer scale. These local atomic arrangements exhibit a striking deviation from the average crystallographic structure featuring different element-specific bond lengths, pronounced bond angle relaxation and severe atomic displacements. The latter, in particular, have a strong influence on the bandgap energy and give rise to a significant contribution to the experimentally observed bandgap bowing. This article therefore reviews experimental and theoretical studies of the atomic-scale structure of III-V and II-VI zincblende alloys and I-III-VI{sub 2} chalcopyrite alloys and explains the characteristic findings in terms of bond length and bond angle relaxation. Different approaches to describe and predict the bandgap bowing are presented and the correlation with local structural parameters is discussed in detail. The article further highlights both similarities and differences between the cubic zincblende alloys and the more complex chalcopyrite alloys and demonstrates that similar effects can also be expected for other tetrahedrally coordinated semiconductors of the adamantine structural family.
- OSTI ID:
- 22482267
- Journal Information:
- Applied Physics Reviews, Vol. 2, Issue 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1931-9401
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTROSCOPY
ALLOYS
ATOMIC DISPLACEMENTS
BOND ANGLE
BOND LENGTHS
CHALCOPYRITE
CORRELATIONS
CRYSTALLOGRAPHY
GALLIUM ARSENIDES
RELAXATION
SEMICONDUCTOR MATERIALS
X-RAY SPECTROSCOPY
ZINC SULFIDES