The relationship between carrier mobility and bicrystalline grains boundary of rutile TiO2 film

摘要

The rutile titanium dioxide (TiO2) has attracted enormous interest in sensor field owing to its stability at high temperature. But less is known about electron transfer efficiency of rutile TiO2, which is mainly influenced by the electron mobility. The aim of this study is to investigate the relationship between carrier mobility and bicrystalline grains boundary of rutile TiO2 film. In this study, TiO2 film was deposited by the direct current pulsed magnetron sputtering technology with sputtering power from 150 to 900 W. Then the TiO2 films were annealed at 1000 degrees C in air atmosphere. By this way, the rutile TiO2 films were obtained. Special attention was paid to the carrier mobility of rutile TiO2 films. The Hall measurement results showed that with the increase of sputtering power from 150 to 900 W, the carrier mobility of rutile TiO2 films increased from 0.75 to 38.88 cm(2)/V . s, gradually. Taking the TEM and SAED results together, our data indicated that the carrier mobility of rutile TiO2 film was influenced by the bicrystalline grains boundary. The large angle bicrystalline grain boundary seriously deteriorates the carrier mobility of rutile TiO2 film. On the contrary, the low angle bicrystalline grain boundary has little influence on the carrier mobility of rutile TiO2 film.