P-type zinc oxide Nano-structure uniform thin film deposited by spray pyrolysis technique: Nitrogen portion variation at precursor solution

Abstract

Thin films of nitrogen doped zinc oxide (ZnO:N) with different nitrogen to zinc atomic ratio (N/Zn) have been deposited by the spray pyrolysis technique. N/Zn has been changed from 0.1 to 3. According to the XRD results, the variation of N/Zn reveals that the crystal orientation transition from (002) to (100) and (101) begins at N/Zn = 1, while for N/Zn=3, (002) orientation almost disappears and (100) would be the dominant crystal orientation. Optical properties of ZnO:N thin films demonstrate a drastic diminution of transmission in visible spectra region from N/Zn = 1 to N/Zn = 3. Hall effect measurement studies of ZnO:N thin films confirmed the effective role of N/Zn on changing the type of conductivity from n to p for N/Zn=3. SEM images illustrate that increasing the nitrogen ratio in precursor solution induces a drastic change in the surface morphology from nano scale mono dispersed spherical grains to plume-like one.