Effect of indium doping in CdO thin films prepared by spray pyrolysis technique

• Published in: The Journal of physics and chemistry of solids Vol. 71; no. 11; pp. 1545 - 1549
• Main Authors: Kumaravel, R., Ramamurthi, K., Krishnakumar, V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2010
• Subjects: A. Thin films; C. X-ray diffraction; D. Electrical properties; D. Optical properties; Doping; Electrical resistivity; Indium; Optical properties; Scanning electron microscopy; Spray pyrolysis; Thin films; X-rays; A. Thin films; C. X-ray diffraction; D. Optical properties; D. Electrical properties
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2010.07.021

Preparation of transparent and conducting indium doped CdO thin films by spray pyrolysis on glass substrate is reported for various concentration of indium (2–8 wt%) in the spray solution. The electrical, optical and structural properties of indium doped CdO films were investigated using different techniques such as Hall measurement, optical transmission, X-ray diffraction and scanning electron microscope. X-ray analysis shows that the undoped CdO films are preferentially orientated along (2 0 0) crystallographic direction. Increase of indium doping concentration increases the films packing density and reorient the crystallites along (1 1 1) plane. A minimum resistivity of 4.843×10 −4 Ω cm and carrier concentration of 3.73×10 20 cm −3 with high transmittance in the range 300–1100 nm were achieved for 6 wt% indium doping. The band gap value increases with doping concentration and reaches a maximum of 2.72 eV for 6 wt% indium doping from 2.36 eV of that of undoped film. The minimum resistivity achieved in the present study is found to be the lowest among the reported values for In-doped CdO films prepared by spray pyrolysis method.