The effects of thermal annealing and exposure to oxygen plasma on the electrical and photoelectric properties of metal-TiO2-Si structures are investigated. The TiO2 films are fabricated by the rf magnetron sputtering of a titanium-oxide target onto unheated n-Si substrates. The forward and reverse currents of the structures after annealing in argon at 500°C are lower than those after annealing at 750°C. Exposure of the titanium-dioxide films to oxygen plasma led to a decrease in the currents at all annealing temperatures. It is supposed that the I–V characteristics of the TiO2-Si structures can be described using the model of space-charge-limited currents. The photoelectric characteristics of the samples are investigated via illumination at a wavelength of λ = 400 nm. The TiO2-Si structures annealed at 500°C without exposure to oxygen plasma exhibit frozen photoconductivity. The relaxation time is 23 ± 2 min.