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 s<<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 5×10^–11 cm²/V and is independent of current level.