Releasable AlGaN/GaN 2D Electron Gas Heterostructure Membranes for Flexible Wide‐Bandgap Electronics

Abstract The development of transferrable free‐standing semiconductor materials and their heterogeneous integration to arbitrary substrates open up new possibilities in improving device performance, exploring nonconventional manufacturing approaches, and offering a pathway to soft, conformal, and flexible electronics. In this work, flexible AlGaN/GaN high‐electron mobility transistors (HEMTs) are demonstrated, which are transfer‐printed from AlGaN/GaN on insulator to a flexible substrate using a novel releasing strategy based on the fast, facile, and reliable transfer process. Flexible AlGaN/GaN HEMTs possess good electrical performance such as the maximum saturated drain current density and transconductance of 110 mA mm −1 and 42.5 mS mm −1 , respectively. Moreover, a significant piezoelectric behavior is observed when the device is under strain, resulting from the piezoelectric‐induced polarization at the heterostructure interface. Owing to an additional strain‐induced piezoelectric effect by the mechanical bending, the performance of AlGaN/GaN HEMT can be further improved. The results demonstrate that the device has great potential in applications for the next‐generation flexible electronics, such as wearable systems, intelligent microinductor systems, and smart systems that can sense or feedback external mechanical stimuli.