A unique photo charge behaviour of bare-KTaO3

Abstract A deep understanding of UV light response of KTaO3 (KTO) has been explored by means of temperature dependent UV treatment. Two different temperature dependent measurement schemes have been utilized to differentiate between the shallow carriers and deep carriers. A fake transition at 220 K is found, which is actually due to the UV-induced oxygen sub-bands, resulting in the transition in photo-response from transient to persistent. Giant change in the resistance is observed for cooling as compared to heating of substrate, which is credited to the small recombination rate at low temperatures. This temperature dependent resistance response of KTaO3 under UV light provides an importance of the measurement way of photo-charge carriers in KTaO3.