Studies on nanocrystalline cadmium sulphide (CdS) thin films deposited by spray pyrolysis

• Published in: Solid state sciences 2010-07, Vol.12 (7), p.1173-1177
• Main Authors: Yadav, A.A., Barote, M.A., Masumdar, E.U.
• Format: Article
• Language: English
• Subjects: A. Chalcogenides; Applied sciences; B. Chemical synthesis; C. X-ray diffraction; Cadmium; Cadmium sulfides; Compact disks; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; D. Electrical conductivity; D. Optical properties; Deposition; Electrical resistivity; Energy gap; Exact sciences and technology; Materials science; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Production techniques; Scanning electron microscopy; Spray coating techniques; Spray pyrolysis; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Surface treatment; Thin films
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2010.04.001

Cadmium chalcogenides with appropriate band gap energy have been attracting a great deal of attention because of their potential applications in optoelectronic devices. CdS in the form of thin film is prepared at different substrate temperatures by a simple and inexpensive chemical spray pyrolysis technique. The as-deposited thin films have been characterized by XRD, SEM, EDAX and electrical resistivity measurement techniques. The XRD patterns show that the films are polycrystalline with hexagonal crystal structure irrespective of substrate temperature. SEM studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire surface of the substrates. Compositional analysis reveals that the material formed is stoichiometric at the optimized substrate temperature. The optical band gap energy is found to be 2.44 eV with direct allowed band-to-band transition for film deposited at 300°C. The electrical resistivity measurement shows that the films are semiconducting with a minimum resistivity for film deposited at 300°C. The thermoelectric power measurement shows that films exhibit n-type of conductivity. [Display omitted]