Effect of ultraviolet radiation on slow-relaxation processes in ferroelectric capacitance structures

The effects of ultraviolet (UV) irradiation on the relaxation processes in Ba 0.3 Sr 0.7 TiO 3 thin film capacitors were experimentally investigated in a range of wavelengths λ = ( 310 - 400 ) nm . It was observed that irradiation with a specific wavelength reduces the time of slow capacitance relaxation up to three orders of magnitude in comparison with relaxation time in the "dark" regime. It was also observed that at a certain wavelength of UV irradiation there was a maximum in the leakage current of the capacitors. This wavelength corresponded exactly with a minimum in the relaxation time of the capacitance. It was shown that the decrease in the ferroelectric film thickness resulted in a shift in τ ( λ ) minima and I ( λ ) maxima towards the shorter wavelengths. Phenomena observed are analyzed using Bouguer's law.