Spectroscopic ellipsometry, optical, structural and electrical investigation of sprayed pure and Sn-doped ZnO thin films

Abstract

In this work, we report the transparent pure and Sn-doped zinc oxide (ZnO). The films were deposited onto microscope glass substrate which was heated at 350±5C by ultrasonic spray pyrolysis (U S P) deposition technique. The concentrations of Sn were selected within the range of 0-3% by step of 0.5% and the time deposition is kept at 5 min. A (002)-oriented wurtzite crystal structure was confirmed by X-rays patterns; and grain size varied within the range 7.37-14.84nm, and cristanillity is calculated goes from14.4 to 45.9%. Based on UV-VIS-IR analysis, the results revealed the high transparency of the sprayed films which exceeds 90%. The band gap energy was of 3.26-3.30 eV. The film thickness was estimated by spectroscopy ellipsometry and the found values were of 165-270nm. The refractive index is in the range of 2.75.The obtained electrical parameters were around 1018 cm-3, 3.6 cm 2/Vs, 1.6Ω.cm; 5.8cm3/C. finally the Sn-doping has influenced the physical parameters of asground ZnO films © Owned by the authors, published by EDP Sciences, 2013.