Dependence of Electrical Properties on Thermal Temperature in Nanocrystalline SnO_2 Thin Films

摘要

Nanocrystalline SnO_2 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℃ with a step of 50℃, respectively. The investigation of X-ray diffraction confirmed that the various SnO_2 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 SnO_2 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 mΩ-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 SnO_2 thin films which composed of nanoparticles.