Room–Temperature Terahertz Detector Based on Monolayer Graphene Integrated with an Asymmetric Bowtie Antenna

Abstract

Terahertz (THz) technology has great potential for applications in various fields, such as security imaging detection, optical communication, environmental quality monitoring, and life sciences. Most of these applications require THz detectors with high sensitivity, fast response, and a miniaturized size that can operate at room temperature. In this study, we present a graphene THz detector integrated with an asymmetric bowtie antenna. The asymmetric antenna confines the incident THz waves into the graphene active layer, leading to photocurrent generation and its directional flow. The maximum responsivity of this device can reach 19.6 V/W at 2.52 THz, with a noise–equivalent power (NEP) of 0.59 nW /Hz0.5. Additionally, the response time is less than 21 μs, with an active area of less than 1500 μm2. Such a small device enables THz imaging with a spatial resolution as small as 200 μm. These results provide a feasible way to design miniaturized and integrable two–dimensional material–based THz detectors.