Optical properties of sol gel dip coated sno2 films

G. Ramanathan and K.R.Murali

In this paper we have reported on dip coating SnO2 films prepared on clean glass substrate post heat treated at different temperature in the range of 350-525°C. X-ray diffraction pattern indicate the films were single phase tetragonal structure. The room temperature PL spectra of the samples show that an intensive Ultra Violet peak at 390 nm (about 3.18eV) and a shoulder at 430 nm (about 2.88eV) are observed in two different temperatures (450oC and 525oC). In addition there is a broad peak at 520 nm (about 2.38eV). Transmission spectra exhibit good transparency in the visible region. The films thickness was estimated using surface profilometer and found to be in the range of 500-640 nm.

The value of some important parameters refractive index (n), extinction coefficient (K) and dielectric constant (ɛ) of SnO2 thin films are determined from the transmission spectra. The energy band gaps of the films are found to vary from 3.68 eV to 3.88 eV. Refractive index was in the range of 2.05-2.18. The dispersion of refractive index was analyzed by W.D single oscillator method. The optical band gap (Eg), dispersion energy (Ed) single oscillator energy (Eo) and optical conductivity were estimated and these films would be suitable for the application of solar cells and sensors.

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DOI: http://dx.doi.org/10.24327/ijcar.2017.5892.0827
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