Electronic and structural properties of A Al{sub 2}Se{sub 4} (A=Ag, Cu, Cd, Zn) chalcopyrite semiconductors
- National Institute of Technology, Rourkela-769008, Odisha (India)
We have studied the structural and electronic properties of defect chalcopyrite semiconductors A Al{sub 2}Se{sub 4} (A=Ag, Cu, Cd, Zn) using density functional theory (DFT) based first principle technique within tight binding linear muffin-tin orbital (TB-LMTO) method. Our calculated structural parameters such as lattice constants a and c, tetragonal distortion ({eta}=c/2a) are in good agreement with experimental work. Anion displacement parameters, bond lengths and bulk modulus are also calculated. Our band structure calculation suggests that these compounds are direct band gap semiconductors having band gaps 2.40, 2.50, 2.46 and 2.82 eV for A Al{sub 2}Se{sub 4} (A=Ag, Cu, Cd, Zn) respectively. Calculated band gaps are in good agreement with other experimental and theoretical works within LDA limitation. We have made a quantitative estimation of the effect of p-d hybridization and structural distortion on the electronic properties. The reduction in band gap due to p-d hybridization is 19.47%, 21.29%, 0% and 0.7% for A Al{sub 2}Se{sub 4} (A=Ag, Cu, Cd, Zn) respectively. Increment of the band gap due to structural distortion is 11.62%, 2.45%, 2.92% and 9.30% in case of AgAl{sub 2}Se{sub 4}, CuAl{sub 2}Se{sub 4}, CdAl{sub 2}Se{sub 4} and ZnAl{sub 2}Se{sub 4} respectively. We have also discussed the bond nature of all four compounds. - Graphical abstract: Band structure and TDOS show the band gaps and effect of structural distortion on electronic properties. PDOS shows effect of p-d hybridization on band gaps for all four compounds. Highlights: > (Ag/Cu/Cd/Zn)Al{sub 2} Se{sub 4} have direct band gap of 2.4, 2.5, 2.46 and 2.82 eV respectively. > p-d hybridization reduces band gaps by 19.5%, 21.3% for (Ag/Cu)Al{sub 2}Se{sub 4} respectively. > No effects of? p-d hybridization on the band gaps for (Cd/Zn)Al{sub 2}Se{sub 4} and ZnAl{sub 2}Se{sub 4}. > Significant enhancement in band gap due to structural distortion in all the compounds. > Effects of bond nature on band gaps are also studied in all the compounds.
- OSTI ID:
- 21580141
- Journal Information:
- Journal of Solid State Chemistry, Vol. 184, Issue 7; Other Information: DOI: 10.1016/j.jssc.2011.04.036; PII: S0022-4596(11)00217-9; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electronic structure theory of chalcopyrite alloys, interfaces, and ordered vacancy compounds
Zn-Al layered double hydroxide prepared at different molar ratios: Preparation, characterization, optical and dielectric properties
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANIONS
BOND LENGTHS
CHALCOPYRITE
DEFECTS
DENSITY FUNCTIONAL METHOD
HYBRIDIZATION
LATTICE PARAMETERS
PALLADIUM OXIDES
SEMICONDUCTOR MATERIALS
CALCULATION METHODS
CHALCOGENIDES
CHARGED PARTICLES
DIMENSIONS
IONS
LENGTH
MATERIALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM COMPOUNDS
SULFIDE MINERALS
TRANSITION ELEMENT COMPOUNDS
VARIATIONAL METHODS