Dependence of Electrical Properties on Thermal Temperature in Nanocrystalling SnO₂ Thin Films

Nanocrystalline SnO₂ thin films were prepared by pulsed laser deposition techniques on clean glass substrates, and the films were then annealed for 30 min from 50 to 550 degrees C with a step of 50 degrees C, respectively. The investigation of X-ray diffraction confirmed that the various SnO₂ thin films were consisted of nanoparticles with average grain size in the range of 23.7-28.9 nm. Root-mean-square surface roughness of the as-prepared SnO₂ thin film was measured to be 25.6 nm which decreases to 16.2 nm with thermal annealing. Electrical resistivity and refractive index were measured as a function of annealing temperature, and found to lie between 1.24 to 1.45 m Omega-cm, and 1.502 to 1.349, respectively. The results indicate that nearly opposite actions to root-mean-square surface roughness and electrical resistivity make a unique performance with thermal annealing temperature. The post annealing shows greater tendency to affect the structural and electrical properties of SnO₂ thin films which composed of nanoparticles.