Transparent phototransistor with high responsivity, sensitivity, and detectivity from heterojunction metal oxide semiconductors

Abstract

In this work, the high-performance transparent Al:InZnSnO/InZnO/Al:InZnSnO tri-layer thin-film phototransistors are reported. They show a high field-effect mobility of 40.1cm(2)/V.s and an excellent high photoresponsivity of 25 000A/W, a photosensitivity of 3.3x10(7), a specific detectivity of 4.3x10(17)cm.Hz(1/2).W-1 under the illumination at 460nm with an intensity of 140 mu W/cm(2). The persistent photoconductivity inherent in phototransistors made of oxide semiconductors overcome by a pulsed gate bias with 1 mu s, which accelerates the recombination of photogenerated holes with electrons. This demonstrates that the transparent photosensor array can be integrated monolithically on the display without appreciable loss of transparency for high functionality such as large area image sensor.