Photoelectric properties of defect chalcogenide HgGa{sub 2}X{sub 4} (x=S, Se, Te)

Journal Article · Fri May 06 00:00:00 EDT 2016 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4946191· OSTI ID:22591305

Sharma, Ramesh ^[1]; Dwivedi, Shalini; Sharma, Yamini ^[2]

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1. Dept. of Physics, Mewar University, Chittorgarh Rajasthan-India (India)
2. Theoretical Condensed Matter Physics Laboratory, Dept. of Physics, Feroze Gandhi College, Raebareli-229001 U.P (India)

We present results of ab initio study of ordered vacancy compounds of mercury. The electronic structure, charge density, optical and transport properties of the semiconductor family HgGa{sub 2}X{sub 4} (X=S, Se, Te) are calculated using the full potential linearized augmented plane wave method which is based on the density functional theory. A direct bandgap is observed in these compounds, which reduces in the order S>Se>Te. From the density of states it is observed that there is strong hybridization of Hg-d, Ga-d and X-p states. The optical properties show a red shift with increasing size and atomic no. of the chalcogenide atoms. We have also reported the transport properties of mercury thiogallates for the first time. The selenide compound exhibits n-type nature whereas HgGa{sub 2}S{sub 4} and HgGa{sub 2}Te{sub 4} show p-type behavior. The power factor and ZT for the HGS increases at low temperatures, the figure of merit is highest for HgGa{sub 2}Se{sub 4} (1.17) at 19 K.

• OSTI ID: 22591305
• Journal Information: AIP Conference Proceedings, Vol. 1728, Issue 1; Conference: ICC 2015: International conference on condensed matter and applied physics, Bikaner (India), 30-31 Oct 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMS
CHARGE DENSITY
DENSITY FUNCTIONAL METHOD
DENSITY OF STATES
ELECTRONIC STRUCTURE
GALLIUM SELENIDES
GALLIUM SULFIDES
GALLIUM TELLURIDES
MERCURY COMPOUNDS
N-TYPE CONDUCTORS
OPTICAL PROPERTIES
P STATES
POTENTIALS
POWER FACTOR
P-TYPE CONDUCTORS
RED SHIFT
TEMPERATURE DEPENDENCE
VACANCIES
WAVE PROPAGATION