Sensor and Electrical device

(a) Schematic diagram of transparent heterojunction all oxide photo TFT. (b) Cross-sectional transmission electron microscope image of the channel layer. (c) Transmittance of the transparent photo TFT array fabricated in 300 pixels per inch. (d) Typical transfer characteristics and the field-effect mobility of our photo TFT in the dark.

In this study, the high-performance transparent Al:InZnSnO /InZnO/Al:InZnSnO (AIZTO/IZO/AIZTO) tri-layer thin-film phototransistors are reported. They show a high field-effect mobility of 40.1 cm2/V·s and an excellent high photoresponsivity of 25,000 A/W, a photosensitivity of 3.3×107, a specific detectivity of 4.3×1017 cm·Hz1/2·W-1 under the illumination at 460 nm with an intensity of 140 μW/cm2. The persistent photoconductivity inherent in phototransistors made of oxide semiconductors overcome by a pulsed gate bias with 1 μs, which accelerates the recombination of photogenerated holes with electrons. This demonstrate 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.

 

In addition, we are conducting research on improving the properties of thin films through plasma treatment and synthesis of thin films for application to sensors.