Optical energy gap of single crystal

Abstract

CuAl 2 S 4 single crystals were grown with the constituent elements copper, aluminium and sulphur (purity 6N) as the starting material by the chemical transport reaction method using iodine as a transport agent. Layer-type colourless transparent single crystals were obtained, and the crystal structure of the single crystals was found to be cubic with the lattice constant a = 9.954 Å. The energy bandgap of the CuAl 2 S 4 single crystal was revealed to be direct bandgap, and the optical energy gap was found to be 4.10 eV at 10 K.

Synthesis, structure, optical properties, and electronic structure of NaLiCdS2

“…4b) and (ahn) 1/2 vs. hn (Fig. 4c) show that the optical transition is indirect [29,30]. The optical transition was determined to be indirect because the fit in Fig.…”

Sn2SiS4, synthesis, structure, optical and electronic properties

“…4. Based on the diffuse reflectance measurement and the electronic structure calculation, the Sn 2 SiS 4 should possess an indirect band gap of about 2.00 eV [41,42].…”

Syntheses, crystal and electronic structure, and some optical and transport properties of LnCuOTe (Ln=La, Ce, Nd)

“…Because of the higher energy level of the Te 5p level compared to those of S 3p and Se 4p the band gap in LaCuOTe is narrower than those in LaCuOS (3.1 eV) and LaCuOSe (2.8 eV). The fundamental dependence of the absorption coefficient (a) at different energies is given by the expression (ahv) n Ehv ÀE g , where E g is the band gap and n ¼ 1 2 or 2, respectively, for an indirect allowed or a direct allowed transition [44,45]. The value of n also depends on the shape of the density of states.…”