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Article Citation - WoS: 8Citation - Scopus: 10Temperature Effects on Optical Characteristics of Cdse Thin Films(Elsevier Sci Ltd, 2021) Gullu, H. H.; Isik, M.; Surucu, O.; Gasanly, N. M.; Parlak, M.CdSe is one of the significant members of II-VI type semiconducting family and it has a wide range of technological applications in which optoelectronic devices take a special position. The present paper reports the structural and optical characteristics of thermally evaporated CdSe thin films. XRD pattern exhibited preferential orientation along (111) plane while atomic composition analyses resulted in the ratio of Cd/Se as closer to 1.0. Temperature-dependent band gap characteristics of CdSe thin films were investigated for the first time by carrying out transmission experiments in the 10-300 K range. The analyses showed that direct band gap energy of the compound decreases from 1.750 (at 10 K) to 1.705 eV (at 300 K). Varshni model was successfully applied to the temperature-band gap energy dependency and various optical constants were determined. Raman spectrum of CdSe thin films was also presented to understand the vibrational characteristics of the compound. The present paper would provide worthwhile data to researchers especially studying on optoelectronic device applications of CdSe thin films.Article Citation - WoS: 25Citation - Scopus: 25Temperature-Tuned Band Gap Properties of Mos2 Thin Films(Elsevier, 2020) Surucu, O.; Isik, M.; Gasanly, N. M.; Terlemezoglu, M.; Parlak, M.MoS2 is one of the fascinating members of transition metal dichalcogenides and has attracted great attention due to its various optoelectronic device applications and its characteristic as two-dimensional material. The present paper reports the structural and temperature tuned optical properties of MoS2 thin films grown by RF magnetron sputtering technique. It was observed that the atomic composition ratio of Mo:S was nearly equal to 1:2 and the deposited thin films have hexagonal crystalline structure exhibiting Raman peaks around 376 and 410 cm(-1). The band gap energies were determined as 1.66 and 1.71 eV at 300 and 10 K, respectively and temperature dependency of band gap energy was analyzed by means of Varshni and O'Donnell-Chen models. (C) 2020 Elsevier B.V. All rights reserved.Article Citation - WoS: 20Citation - Scopus: 21Temperature-Tuned Band Gap Characteristics of Inse Layered Semiconductor Single Crystals(Elsevier Sci Ltd, 2020) Isik, M.; Gasanly, N. M.Layered structured InSe has attracted remarkable attention due to its effective characteristics utilized especially in optoelectronic device technology. This point directs researchers to investigate optical properties of InSe in great detail. The temperature dependent band gap characteristics of InSe and analyses performed on this dependency have been rarely studied in literature. Here, temperature-dependent transmission and room temperature reflection experiments were performed on InSe layered single crystals. The band gap energy was found around 1.22 eV at room temperature and 1.32 eV at 10 K. The temperature-gap energy dependency was analyzed using Varshni and O'Donnell-Chen models to reveal various optical parameters of the crystal. The structural characteristics; crystalline parameters like lattice constants, lattice strain, dislocation density and atomic compositions of InSe were also determined from the analyses of XRD and EDS measurements.
