Programmable Flexoelectric Engineering of Monolayer β-Te for Polarization-Sensitive Near-Infrared Photodetection

Function-defined flexoelectric bending provides an effective route to regulate the electronic and photoelectric properties of two-dimensional anisotropic semiconductors. Here, we propose a programmable flexoelectric engineering strategy for monolayer β-Te and investigate its near-infrared polarization-sensitive photoresponse using first-principles calculations combined with quantum transport simulations. Three representative bending profiles, denoted as Gau, Para, and Sin, are introduced to mimic localized indentation, global bending, and smooth wrinkle-like deformation, respectively. The results show that β-Te possesses a narrow band gap, strong in-plane anisotropy, and low stiffness, making it suitable for flexoelectric modulation. Function-defined flexoelectric bending effectively narrows the band gap, reconstructs the band-edge electronic states, and enhances bias-window transmission, especially along the zigzag direction. More importantly, the flexoelectrically engineered β-Te devices exhibit significantly enhanced near-infrared polarization-sensitive photocurrent and improved polarization selectivity, with a maximum photoresponse of approximately 35 a02/photon. This work demonstrates that programmable flexoelectric engineering is an efficient strategy for designing flexible, tunable, and high-performance near-infrared polarization-sensitive photodetectors.