Ultrasensitive Room‐Temperature Terahertz Direct Detection Based on a Bismuth Selenide Topological Insulator

Metal‐topological insulator–metal subwavelength structure is proposed to achieve ultrasensitivity, room temperature terahertz photodetectors. Due to peculiar properties of topological surface state (TSS), direct detection of low energy photons can be enabled by a localized THz field, exhibiting both high sensitivity and fast response at the self‐powered and the bias mode, opening up a route for large area, fast imaging.