Influence of substrate temperature on the optical propertiesof ZnO thin films

Abstract

The ZnO thin films were deposited at different substrate temperatures by ultrasonic spray and spraypyrolysis techniques. In this paper we present a new approach to control the optical gap energy of ZnOthin films by varying the substrate temperature. The model proposed to calculate the band gap energywith the Urbach energy was investigated. The relation between the experimental data and theoreticalcalculation suggests that the band gap energies are predominantly estimated by the Urbach energies, filmtransparency and substrate temperatures. The measurements by these proposals model are in qualitativeagreements with the experimental data, which the correlation coefficients values were varied in the range0.96 – 0.99999, indicating high quality representation of data based on Eq. (2), so that the relative errorsof all calculations are smaller than 4%.