Characterization Of Barium Oxide (BaO) Thin Films Synthesized By Chemical Bath Deposition And Successive Ionic Layer Adsorption And Reaction Techniques

                                                                             ABSTRACT

Thin films of barium oxide (BaO) were deposited on glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) and Chemical Bath Deposition (CBD) techniques from aqueous solutions of barium nitrate and potassium hydroxide at room temperature (28°C). The substrates used were commercial glass slides of 76mm x 25 mm thick. The film properties studied include spectral transmittance, reflectance, absorbance, which occurred in the spectral range of 300-900nm in the (UV-VIS-NIR) regions of the electromagnetic spectrum. The films produced fairly high transmission (75% for the SILAR and 84% for the CBD methods), low reflectance (>40% for both SILAR and CBD methods), absorption coefficient of (4.34 x 106m'), optical conductivity of (1.09 x 10'), high refractive index of (3.14) and band gap of(<3.75eV) for indirect transition was obtained. These films could be used as transparent conducting oxides for window layers in solar cell fabrications. The films showed poor absorbance in the UV—VIS-NIR regions. The absorbance decreased with increase in SILAR cycles and annealing temperature from 0.94 to negative values in the wavelength range of 300 — 900nm hence, they have potential applications as thermal control coatings for cold climates and as antireflection material. The films thickness increased with number of SILAR cycles and annealing temperature from 0.1 — 1.0pm. The films also exhibited poor electrical conductivity of (9.911x 10 8 m 1 ) and could be used as an electrical insulator.