AlGaN/GaN‐based Photoimaging Transistors and Arrays with Reconfigurable Triple‐Mode Functionalities Enabled by Voltage‐Programmed Two‐Dimensional Electron Gas

High-quality imaging units are indispensable in modern optoelectronic systems for accurate recognition and processing of optical information. To fulfill massive and complex imaging tasks in the digital age, devices with remarkable photoresponsive characteristics and versatile reconfigurable functions on a single-device platform are in demand but remain challenging to fabricate. Herein, an AlGaN/GaN-based double-heterostructure is reported, incorporated with a unique compositionally graded AlGaN structure to generate a channel of polarization-induced two-dimensional electron gas (2DEGs). Owing to the programmable feature of the 2DEGs by the combined gate and drain voltage inputs, with a particular capability of electron separation, collection and storage under different light illumination, the phototransistor shows reconfigurable multifunctional photoresponsive behaviors with superior characteristics. A self-powered mode with a responsivity over 100 A W