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Effect of DFT methods on electronic structure and K-absorption spectra of InPS4: detailed studies of the optical, thermoelectric and elastic properties


Tuan V Vu, A A Lavrentyev, B V Gabrelian, K F Kalmykova, Dat D Vo*, Hien D Tong, D M Hoat, M Batouche, Hai L Luong, O Y Khyzhun

Source title: 
Materials Research Express, 6(10), 2019 (ISI)
Academic year of acceptance: 

The effect of exchange-correlation potential on InPS4 electronic structure was studied by applying GGA, GGA + U, mBJ, and mBJ + U potentials in the Kohn–Sham framework. The use of mBJ + U in full potential APW + lo method results in reliable K-absorption spectrum, which consists of nearly full experimental peaks of right intensity. The remarkable discrepancy between a occurs at 0 eV, 4 eV, 6 eV, and 9.5 eV, indicating the strong anisotropic optical properties of InPS4 at these energy levels. At 4 eV, a is 37% higher than a The optical absorption of InPS4 has high order of 105cm−1 magnitude for wide energy range, at least within 4–20 eV. The difference in extinction coefficient a is 30%–50% at 4 eV, 6 eV, 8 eV, and 11 eV. The figure of merit ZT of InPS4 is rather low. At n = 8 × 1018 cm−3, ZT achieves its highest value of about 0.8–1. InPS4 is a p-type semiconductor for chemical potential μ ranging from 0 eV to about 1.6 eV, but it is an n-type semiconductor for μ of about 1.6–2.7 eV. The Poisson's ratio is equal to 0.26 and a. Indium thiophosphate InPS4 possesses rather low deformation resistance with the Young and shear moduli of 38.47 GPa and 15.27 GPa, respectively.