RECOMBINATION IN NANOPHASE TIO2 FILMS

Recombination and transport parameters were determined in Schottky diodes made of thin TiO2 solgel films with particle size around 50 nm. Effective recombination times are typically in the range, 10 mus < tau < 1 ms, depending on injection level. The lifetimes are found to decrease at higher current levels, indicating bimolecular recombination kinetics due to a progressive increase in trap occupation. The mobility-lifetime product is estimated to be approximately 5 X 10(-11) cm2/V and is independent of current level.