Electrical transport in passivated Pt/TiO2/Ti Schottky diodes -: art. no. 104501

Pt/TiO2/Ti Schottky diodes were investigated by current-voltage analysis, photoresponse, and transient photocurrent (PC) in a wide temperature range. The compact TiO2 as well as the SiO2 passivation layers were prepared by the sol-gel technique. The Schottky-barrier height (1.2-1.3 eV) was equal to the difference of the work functions of Pt and Ti. The temperature dependence of the ideality factor was interpreted in terms of a Gaussian distribution of barrier heights [J. H. Werner and H. H. Guttler, J. Appl. Phys. 69, 1522 (1991)]. Space-charge-limited currents under the presence of defects with an exponential distribution were observed. Under zero-potential condition, the PC transients were practically independent of temperature and the electron drift mobility amounted to 2x10(-4) cm(2)/(V s). A screening dipole layer at the Pt/TiO2 junction was formed under low forward and reverse potentials. Defects were generated under electron injection. (c) 2005 American Institute of Physics.