Designed Field Localization in 2D Semimetal 1T’-MoTe2 for Tunable Terahertz Photodetection

Abstract

The performance of terahertz photodetectors is critically dependent on efficient signal coupling and carrier transport control. Here, we demonstrate a performance-tunable, room-temperature detector by integrating a bow-tie antenna with a CVD-grown 1T’-MoTe2 channel, where the antenna geometry directly governs the photoresponse. Systematically reducing the channel length strongly enhances the localized electric field intensity (E2), which in turn boosts the photocurrent according to the quantitative scaling law Iph∝ E2/r. This designed tunability yields a device with a maximum responsivity of 3.03 A/W, a noise-equivalent power of 3.1 pW/Hz0.5, a high linearity (α ≈ 0.98), and a fast response time of 2.7 μs across a 0.02−0.3 THz band. We conclude that hybrid structures comprising 2D semimetals and planar antennas provide an effective strategy for designing high-performance, controllable terahertz detection systems.