Optical characterization of nanostructured Ge1 − xSnxSe2.5 (x = 0, 0.3, 0.5) films
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The paper reports the optical properties of thin films of nanostructured Ge1 − xSnxSe2.5 (x = 0, 0.3, 0.5) glassy alloys. The glassy alloys of Ge1 − xSnxSe2.5 (x = 0, 0.3, 0.5) were prepared using melt quenching method. Thin films of nanostructured Ge1 − xSnxSe2.5 (x = 0, 0.3, 0.5) glassy alloys were prepared using physical vapor deposition method. The films were characterized using XRD, EDX and TEM, which confirmed the amorphous nature, composition and formation of nanorods in the samples. Absorption and transmission spectra of thin films were recorded in the spectral range 400–2500 nm to obtain energy band gap, refractive index, extinction coefficient, dielectric constant etc. Results show that refractive index increases while band gap decreases on increase of Sn content in the Ge–Se system. This is due to the increase in density of defect states within band gap. The values of Urbach energy support the obtained results.
KeywordsNanostructured glasses Thin films Optical properties Band gap
First author Deepika is highly thankful to the Department of Science and Technology, Government of India for financial support vide Reference No. SR/WOS-A/PM-1017/2014 under Women Scientist Scheme to carry out this work.
- Deepika, Singh, H.: Study of size distribution in Se58Ge39Pb3 glass using various characterization methods. MAPAN-J. Metrol. Soc. India 33, 165–168 (2018)Google Scholar
- Deepika, Rathore, K.S., Saxena, N.S.: A kinetic analysis on non-isothermal glass-crystal transformation in Ge1 − xSnxSe2.5 (0 ≤ x ≤ 0.5) glasses. J. Phys.: Condens. Matter 21, 335102 (2009b)Google Scholar
- Deepika, Singh, H., Saxena, N.S.: Electrical properties of Ge1Se2.5 and Ge0.6Se2.5Sn0.4 glasses. Mater. Res. Express 4, 035203 (2017)Google Scholar
- Gleiter, H.: Nanoglasses: a new kind of noncrystalline materials. J. Nanotechnol. 4, 517–533 (2013)Google Scholar
- Haynes, W.M.: CRC Handbook of Chemistry and Physics, 95th edn. Taylor and Francis, New York (2014–2015)Google Scholar
- Mott, N.F., Davis, E.A.: Electronic Processes in Non-crystalline Materials. Clarendon Press, Oxford (1979)Google Scholar
- Rashad, M., Amin, R., Hafiz, M.M.: Blue shift in the optical band gap of amorphous nanostructure Se80Te20 − xSnx. Chalcogenide Lett. 12, 441–451 (2015)Google Scholar
- Salah, N., Sami, H., Khan, Z.H., Khan, S.A.: Synthesis and characterization of Se35Te65 − xGex nanoparticle films and their optical properties. J. Nanomater. 201, 393084 (2012b)Google Scholar
- Tauc, J.: The Optical Properties of Solids. North-Holland, Amsterdam (1970)Google Scholar