Sub-Skin-Depth Nanoslit Integrated Topological Insulator Devices for Self-Driven Broadband Terahertz Detection and Imaging

Abstract

The advancement of terahertz technology is primarily fueled by the imperative for room-temperature operation with high sensitivity, high integration, and broadband detection capabilities. Nevertheless, the traditional semiconductor materials in terahertz detectors continue to grapple with obstacles, notably intricate integration and processing complexities. The unique electronic structures and non-trivial topological properties of two-dimensional topological materials bring new possibilities and perspectives for high-performance terahertz low-energy photon detection. Here, an antenna combined with the topological insulator GeBi₄Te₇ and an ultrashort channel integration technique is utilized to significantly enhance the electromagnetic response in a confined region by compressing and localizing the optical field in the spatial dimension. This strategy achieves a preferential flow of hot carriers through enhanced light-matter interactions while satisfying the enhanced bandwidth and response speed of the detector. The sensitivity of the detector is 3.04 A·W⁻¹ at 0.81 THz with a noise equivalent power of less than 15.8 pW·Hz^−0.5 and a response time of less than 5 µs. These research results provide a brand-new opportunity to develop highly sensitive, highly integrated, and broadband terahertz detectors, enabling exploration across a diverse array of application domains.