Effect of N Doping on the Optical and Electrical Properties of Thermal Spray Pyrolyzed ZnO Thin Films

Abstract

This paper considers the experimental study of
Nitrogen doped ZnO (ZnO:N) thin films deposited on a
glass substrate at 350ºC using low cost homemade
thermal spray pyrolysis technique in a typical
environmental condition. In this study the average
reflectance, transmittance, and absorbance were
experimentally measured 20%, 35%, and 45%,
respectively. Absorption coefficient is obtained 3.5x104
cm-1 for N doped ZnO sample. However, direct bandgap
energy varies from 3.08 to 2.99 eV and indirect band gap
energy varies from 2.86 to 2.67 eV. XRD analysis shows
that the (002) plane is present in the experimental sample
and the average grain size decreases with the increasing
N concentration. Surface morphology of the sample is
studied by Scanning Electron Microscopy. It is seen that
few voids are present in the hexagonal crystal grains. The
surface exhibits more or less uniform surface
morphology with some clusters on the whole surface.
Hall Effect study confirms that Nitrogen doped ZnO
(ZnO:N) thin films using Vander Pauws method were
made at room temperature at a constant field of 9.75 KG.
Experimentally (1, 2, 3, and 4) % N doped ZnO thin films
have shown negative Hall Constant (RH), which exhibits
N-type characteristics. RH and Hall concentration (n)
increase with increasing N doping concentration.