Cadmium Oxide Thin Films Deposited by a Simplified Spray Pyrolysis Technique for Optoelectronic Applications

Document Type: Research Paper

Authors

Abstract

Cadmium oxide thin films were fabricated on glass substrates by a simplified and low cost spray
pyrolysis technique at different substrate temperatures. The X-ray diffraction study showed that
irrespective of substrate temperature all the films exhibits a preferential orientation along the
(1 1 1) plane. The values of crystallite size were found to be in the range 20.72 – 29.6 nm. The
percentage transmittance and the optical band gap values are found to be in the range of 78 – 89
% and 2.38 – 2.55 eV respectively. The optical transmittance is found to increase gradually with
increase in substrate temperature. Urbach energy decreases with increase in substrate temperature.
Optical parameters such as refractive index and packing density were calculated. The dispersion
parameters of the as-deposited CdO films were calculated to analyze their choice in designing
optical devices. PL studies confirm that the films exhibit strong luminescent properties. The
value of ρ decreases with increase in substrate temperature and attains a minimum value of 0.26 x 10-6
ohm-m for the film coated at 375ºC which has the least thickness.

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