Studies on the structure optical and electrical properties of Zn-doped NiO thin films grown by spray pyrolysis

作者:Sharma Ratnesh*; Acharya A D; Shrivastava S B; Patidar Manju Mishra; Gangrade Mohan; Shripathi T; Ganesan V
来源:Optik, 2016, 127(11): 4661-4668.
DOI:10.1016/j.ijleo.2016.01.050

摘要

Thin films of Ni1-x,ZnxO with different composition (x=0, 0.01, 0.05 and 0.10) were successfully fabricated on glass substrates using spray pyrolysis technique. The as-prepared films were further annealed at 623 K in room atmosphere for 2 h. The evolution of their structural, morphological, electrical and optical properties with annealing temperature was investigated. The result reveals that the annealing of the films leads to improved surface morphology and better crystallinity. The prepared films displayed increase in conductivity followed by decrease in band gap with increase in doping concentration. However, the effect is more significant in case of annealed films, where the average transparency shows an increase of about 10% over the as prepared thin films. The red-shift of the optical band gap is due to the deep states in the band gap. The increase in density of states has been confirmed by variable range hoping (VRH) mechanism. The activation energy was found to be decreased when Zn concentration increased. Added to this the dielectric function of thin films and their spectral variation has been tentatively discussed.

  • 出版日期2016