Effect of Urbach energy with precursor molarity on the crystallite size in undoped ZnO thin film

We investigated the structural and optical properties of ZnO thin films as the n-type semiconductor, the thin films were deposited at different precursor molarities by ultrasonic spray method on glass substrate at 350 degrees C, as discussed in our published paper. In this paper we focused our attention on the present a new approach to the description of correlation between crystallite size and Urbach energy with precursor molarities, this correlation based on experimental data of our study previously published. The correlation between structural and optical properties with precursor molaritie was investigated. The measurement of the crystallite sizes of undoped ZnO thin films were realized at different model proposals; these measurements shows that the crystallite sizes of the films can be estimated by varying the Urbach energy and the concentration of ZnO solution, which are in qualitative agreements with the experimental data. The best estimate result is measured by Equation (9) with minimum relative errors values were limited to 1 %. Thus results indicate that the ZnO thin films are chemically purer and have many fewer defects and less disorder owing to an almost complete chemical decomposition.