Effect of doping concentration and annealing temperature on nitrogen-doped ZnO thin films: an investigation through spectroscopic techniques

Undoped and nitrogen-doped ZnO (NZO) thin films were deposited by sol-gel spin-coating technique on glass substrates. The thin film preparation was accomplished using zinc acetate dihydrate, monoethanolamine and 2-methoxyethanol as the precursors. Ammonium acetate was used as the source of nitrogen for doping. The effect of dopants and the post-heating temperature on the various physical properties of the deposited films was explored. The X-ray diffraction studies reveal the polycrystalline nature of the films which possess a preferred c-axis orientation. Raman characterizations of the films show a clear indication of nitrogen incorporation in the films. The carrier concentration of the thin films was of the order of 10(17)/cm(3) and resistivity as minimum as 0.371cm was observed for 1at.% NZO thin films post-heated at 500 degrees C. The 1at.% and 2at.% doped NZO films post-heated at 300 degrees C and 1at.%, 2at.% and 3at.% doped NZO films with post-heat treatment at 500 degrees C exhibited p-type conductivity. In the aging study, 500 degrees C annealed films retained p-type conductivity for 5days.