I-V and C-V characteristics of Au/TiO2 Schottky diodes

Abstract
The electrical characteristics of Au/n-TiO2 Schottky diodes have been studied using I-V and C-V measurements. TiO2 samples with working face perpendicular to the c axis are reduced in a vacuum of 10−6 Torr at 800 °C for about 5 h and then quenched. The resistivities are in the range 20–30 Ω cm. The barrier heights deduced from I-V characteristics in agreement with the thermionic emission theory are in the range 0.87–0.94 eV. C-V data yield lower barrier heights and show a frequency dependence attributed to relaxation phenomena occurring in a disturbed layer near the surface. Comparison with results relative to Au/n-SrTiO3 diodes shows that the barrier heights obey the Schottky model for these ionic semiconductors, confirming the role of the electron affinity in the band bending formation.