Freestanding Crystalline β-Ga<sub>2</sub>O<sub>3</sub> Flexible Membrane Obtained via Lattice Epitaxy Engineering for High-Performance Optoelectronic Device
Chao Lu, Mengcheng Li, Lei Gao, Qinghua Zhang, Mingtong Zhu, Xiangyu Lyu, Yuqian Wang, Jin Liu, Pengyu Liu, Lu Wang, Huayu Tao, Jiayi Song, Ailing Ji, Peigang Li, Lin Gu, Zexian Cao, Nianpeng Lu
Abstract
Wearable and flexible β-Ga 2 O 3 -based semiconductor devices have attracted considerable attention, due to their outstanding performance and potential application in real-time optoelectronic monitoring and sensing. However, the unavailability of high-quality crystalline and flexible β-Ga 2 O 3 membranes limits the fabrication of relevant devices. Here, through lattice epitaxy engineering together with the freestanding method, we demonstrate the preparation of a robust bending-resistant and crystalline β-Ga 2 O 3 (−201) membrane. Based on this, we fabricate a flexible β-Ga 2 O 3 photodetector device that shows comparable performance in photocurrent responsivity and spectral selectivity to conventional rigid β-Ga 2 O 3 film-based devices. Moreover, based on the transferred β-Ga 2 O 3 membrane on a silicon wafer, the PEDOT:PSS/β-Ga 2 O 3 p–n heterojunction device with self-powered characteristic was constructed, further demonstrating its superior heterogeneous integration ability with other functional materials. Our results not only demonstrate the feasibility of obtaining a high-quality crystalline and flexible β-Ga 2 O 3 membrane for an integrated device but also provide a pathway to realize flexible optical and electronic applications for other semiconducting materials.