International Journal of Latest Technology in Engineering, Management & Applied Science (IJLTEMAS) Volume VI, Issue V, May 2017 | ISSN 2278-2540 www.ijltemas.in Page 68 Characterization Studies of CdS Nanocrystalline Film Deposited on Teflon Substrate Lekha Verma 1 , Dipali Soren 2 , Sandhya Pillai 3 , Prashant Shrivastava 4 1, 2, 4 ETC Department, CCET Bhilai, India 3 PHYSICS Department, CCET Bhilai, India Abstract:- In this article, different substrates for deposition of CdS material have been discussed. Till date glass, mica, quartz, ceramic, etc. are commonly employed substrates in thin film growth. In the present work, CdS is deposited on Teflon substrate by chemical bath deposition (CBD) method. Also the films were deposited on different substrates like glass, copper and zinc and compared with those prepared on Teflon substrate. The films prepared on Teflon substrate were uniform, stable and also showed good radiating property. These films were further characterized by UV-VIS absorption spectral studies, SEM and EDS studies. Keywords: Teflon, CdS, SEM, substrate I. INTRODUCTION he deposition of thin films require certain supporting materials called substrate. Substrate may be amorphous, polycrystalline or single crystal in nature. Glass, mica, quartz, ceramic, etc. are commonly employed substrates in thin film growth. Recently, efficient polycrystalline films are being deposited on polymer substrates, such as polycarbonate and polyethylene terephthalate as they are light weight, of small volume and can make the obtained devices foldable and also easy to carry [1]. Cadmium sulfide, CdS is a II–VI semiconductor compound. It is a wide and direct band gap (2.42 eV) material at room temperature and has good optical transmittance, low resistivity and easy ohmic contact. CdS surface quality depends on the method used for film preparation, and also requires that the films be free of voids, grain frontiers, etc., and to be capable to achieve minimum thicknesses to reduce optical losses. [2] CdS material has been synthesized by different techniques like CBD, Sputtering, Electro chemical deposition etc. This material shows interesting optical and electrical properties and hence is used in solar cells, as pigment, photovoltaic devices, and sensors. Nanocrystalline materials are becoming increasingly interesting for optoelectronics and photonics. The electronic and electrical properties of such materials show a remarkable change as the particle size approaches that of its excitonic Bohr radius and then electrons and holes are subject to quantum confinement effects [3, 4] due to their large surface to volume ratios resulting in high density of surface states. These nano particles with tailored physical properties have potential application in the fields of molecular level electronic and photovoltaic devices [5], [6], catalysis, molecular diagnostics and interfacial electron transfer [7] This paper mainly focus on different substrate study and properties of CdS material. II. MATERIALS AND METHODS Thin films were deposited on teflon substrate (22mm L × 16 mm wide), thickness 1.5 mm (±0.1 mm) with dielectric constant of 2.1. The teflon substrates were first washed with concentrated HCl and acetone .After that the slides were thoroughly washed by deionized water several times, For the bulk CdS film, 1M Cadmium Acetate Triethanolamine, Thiourea and aqueous Ammonia were added. For the nano crystalline film, mercaptoethenol (MEL) as capping agent and methanol (used for dissolving MEL) were added. In the beginning when precipitation started, stirring was done using magnetic stirrer for 5min. After that the deposition was made in static condition in the water bath at temperature 60 0 C. During which the solution color changed to yellow as the deposition time increases. At the end of the deposition, CdS thin film was formed on the substrates with desired thickness, was adherent, homogeneous and yellowish without any powder precipitation. The substrates were removed from the chemical bath, rinsed thoroughly in distilled water and dried in the air at room temperature. The surface morphology and chemical composition of the films were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) using S- 48500 type-II (Hitachi High Technology Corporation Tokyo, Japan). The optical properties of the films were determined by ELICO SL210 UV-VIS Spectro photometer. Fig 1 deposition of CdS on Teflon substrate T