Optical properties of Tl2InGaS4 layered single crystal

✍ Scribed by A.F. Qasrawi; N.M. Gasanly

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 175 KB
• Volume: 29
• Category: Article
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2006.09.008

✦ Synopsis

The temperature dependence of the optical band gap of Tl 2 InGaS 4 single crystal in the temperature region of 300-500 K and the room temperature refractive index, n(k), have been investigated. The absorption coefficient, which was calculated from the transmittance and reflectance spectra in the incident photon energy range of 2.28-2.48 eV, increased with increasing temperature. Consistently, the absorption edge shifts to lower energy values as temperature increases. The fundamental absorption edge corresponds to an indirect allowed transitions energy gap (2.35 eV) that exhibits a temperature coefficient of À4.03 • 10 À4 eV/K. The room temperature n(k), calculated from the reflectance and transmittance data, allowed the identification of the oscillator strength and energy, static and lattice dielectric constants, and static refractive index as 16.78 eV and 3.38 eV, 5.96 and 11.77, and 2.43, respectively.