Depletion-Mode A-GaO Solar-Blind Phototransistors for Optoelectronic Mixed Logic Gate Circuit and Solar-Blind Imaging.

Phototransistors based on GaO are widely used in civil or military applications as a three-terminal device with solar-blind characteristics. This study constructed amorphous gallium oxide (a-GaO) thin film transistor (TFT)-based solar-blind photodetectors and explored the effect of the oxygen partial pressure on films and devices. It had been found that there is a strong correlation between oxygen partial pressure and photodetector properties. Decreasing oxygen partial pressure increases the carrier concentration, resulting in a shift of device threshold voltage () from 15 V to -5 V, thereby causing the device to transition from enhancement mode to depletion mode. And the a-GaO TFT-based solar-blind photodetector in depletion mode has an ultrahigh performance, with a responsivity () of 1038 A/W and an / ratio of 10 at a gate voltage (V) of -5 V and a responsivity of 2100 A/W at a of 100 V. And the reconfigurable basic logic functions ("AND"/"OR") have been achieved. Furthermore, the imaging is realized by assembling a-GaO thin film transistor-based solar-blind photodetector arrays (a-GaO TFT-PDAs).