Edge-Dominated Epitaxy of Topological Insulator Bi<sub>2</sub>Se<sub>3</sub> with Ultrabroadband Response
Tiange Zhao, Shijie Duan, Wenzhen Dou, Tengfei Xu, Xiaoyun Wang, Yuzhuo Bai, Lin Wang, Liang Ma, Jun Wang, Jun Wang, Zhen Wang, Jianbin Xu, Jinlan Wang, Jinlan Wang, Xinran Wang, Weida Hu
Abstract
Topological insulators, as a typical quantum state with robust spin–orbit coupling and topologically protected surface states, hold transformative potential for next-generation information devices. However, current fabrication approaches face critical limitations in thermodynamic uniformity and kinetic precision, hindering the scalable synthesis of high-quality crystals. Herein, we propose a flow-confined epitaxy strategy to synthesize large-scale Bi 2 Se 3 topological insulators. Precisely regulating the chemical potential and reaction kinetics ensures atomic-level thermodynamic homogeneity and suppressed parasitic nucleation. The edge-dominated lateral diffusion mechanism enables the synthesis of millimeter-scale high-quality Bi 2 Se 3 single crystals and 2-in. wafer-scale highly oriented Bi 2 Se 3 crystals. Furthermore, through the construction of a 16 × 16 array, we demonstrate the ultrabroadband (520 nm–0.1 THz) and uniform response with excellent sensitivity of Bi 2 Se 3 devices. This work presents a universal epitaxial paradigm for scalable topological insulator synthesis, which supports future integration into quantum photonic circuits and high-performance optoelectronic devices.