The crystal and electronic band structure of the diamond-like semiconductor Ag2ZnSiS4

Abstract

► The structure of Ag 2 ZnSiS 4 is solved and refined in the space group Pn using single crystal X-ray diffraction. ► Electronic band structure calculations show that Ag 2 ZnSiS 4 is a direct band gap semiconductor with a calculated band gap of 1.88 eV. ► The optical band gap of Ag 2 ZnSiS 4 was experimentally determined as 3.28 eV. Single crystals of the new diamond-like semiconductor Ag 2 ZnSiS 4 have been synthesized using high-temperature, solid state synthesis at 800 °C. The compound crystallizes in the monoclinic, noncentrosymmetric space group Pn with a = 6.4052(1) Å, b = 6.5484(1) Å, c = 7.9340(1) Å, β = 90.455(1)° and R 1 (for all data) = 2.42%. The electronic band structure and density of states were calculated using density functional theory (DFT) and the full potential linearized augmented plane wave (LAPW) method within the Wien2k program suite. The calculated band structure suggests that Ag 2 ZnSiS 4 is a direct band gap semiconductor with a calculated band gap of 1.88 eV at the Γ-point. The calculated density of states of Ag 2 ZnSiS 4 is compared with that of AgGaS 2 . The band gap of Ag 2 ZnSiS 4 was also determined experimentally as 3.28 eV via optical diffuse reflectance spectroscopy.