Open AccessStudy of a new layered ternary chalcogenide CuZnTe2 and its potassium intercalation effect
Author(s) -
Md Khadimul Islam,
Md. Abdur Razzaque Sarker,
Yuji Inagaki,
Md. Kamrul Islam
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abbd06
Subject(s) - density functional theory , band gap , debye model , ternary operation , chalcogenide , density of states , condensed matter physics , direct and indirect band gaps , fermi level , materials science , valence (chemistry) , chemistry , intercalation (chemistry) , electronic band structure , ab initio , computational chemistry , inorganic chemistry , electron , physics , organic chemistry , quantum mechanics , computer science , programming language , metallurgy
A new layered ternary chalcogenide CuZnTe 2 and its effect due to potassium (K) intercalation have been investigated using ab-initio method under the framework of density functional theory (DFT). Here, we report the structural, electronic and elastic properties of both proposed parent compound CuZnTe 2 and intercalated KCuZnTe 2 . The electronic band structures and the density of states (DOS) of both these chalcogenides have also been studied. The parent compound demonstrates p -type conductivity with the energy band gap of 0.7 eV but surprisingly, the increase of energy gap (1.5 eV) is found in the intercalated KCuZnTe 2 , a direct-transition type semiconductor. The optical absorption result in KCuZnTe 2 also shows the identical value of gap energy calculated by Wood-Tauc theory. The density of states (DOS) in the valence band for both compounds is dominated by the partial contribution of Cu/Zn 3 d and Te 5 p orbitals but the prime contribution of Cu/Zn 4 s and Te 5 s mainly in the conduction band DOS. The DOS value at around Fermi level in these chalcogenides is indicating the degeneracy behavior of a semiconductor. Both compounds are mechanically stable and also malleable. We also calculated the thermal properties in the intercalated KCuZnTe 2 using quasi-harmonic Debye model. The observed values of Debye temperature, specific heat capacities and volume expansion coefficient using this model is almost consistent with the estimated values given in theory.