Atomistic aspects of carrier concentration variation in post-annealed indium tin oxide films

Post-annealing environment-dependent optical and electrical properties of indium tin oxide films grown on glass were examined. X-ray diffraction measurements revealed that all of the films exhibited poly-crystallinity after annealing at 400 °C for 10 min O₂, in-air and N₂. The optical property measurements yielded >80% transmittances for all the films except for the as-grown and O₂-annealed films, even though there were no significant optical band-gap energy differences. In the Hall measurements, all of the films exhibited n-type characteristics. However, the film annealed under the N₂ environment showed the best electrical properties (highest carrier concentration and conductivity). The physical origin of electrical property variations due to annealing environment differences was explained by examining the core-level x-ray photoelectron spectra.