Topological Contact-Optimized Te/GaAs van der Waals Heterostructure Array Enabling High-Performance Self-Powered Broadband Photodetectors

Weyl semiconductor Te holds great promise for next-generation optoelectronics due to its ultrahigh carrier mobility and unique topological surface states. However, its practical application is hindered by challenges such as the lack of scalable wafer-scale manufacturing methods for uniform films and high dark current. This study reports an in situ deposition strategy enabling wafer-scale fabrication of 64-pixel GaAs/Te van der Waals heterojunction (vdWH) arrays, achieving ultrawide-band photoresponse from solar-blind to near-infrared. Especially upon 1050 nm illumination, a GaAs/Te unit device exhibits superior performance, including an impressive responsivity of 55 mA/W, a specific detectivity of 2 × 10¹² Jones, and a fast response speed of 2.6/5.1 ms at 0 V bias. Owing to the strong in-plane anisotropy of the Te layer, the detector achieves an anisotropy ratio of 2.57 at 1050 nm. The enhanced performance primarily stems from Te’s topological surface state, which enables robust interlayer coupling with GaAs while effectively suppressing interfacial defects. The GaAs/Te array architecture, enabled by its remarkable spatial uniformity in the pixel arrangement, demonstrates exceptional potential for polarization-encrypted imaging and pixel-level multispectral fusion technologies. Significantly, the implementation of topological vdW contact engineering, coupled with wafer-scale synthesis of Weyl semiconductor Te, establishes a transformative platform for advancing next-generation optoelectronic systems and CMOS-integrated photonic devices.