Oral Presentation

Development of Sensitive Graphene-Based Detectors for Terahertz Imaging Applications (Remote)

Author(s): Wei Miao (Purple Mountain Observatory, PMO), Jiaqiang Zhong (PMO), Wen Zhang (PMO), Jing Li (PMO), Shengcai Shi (PMO), Cui Yu (Hebei Semiconductor Research Institute, HSRI), Zezhao He (HSRI), Qinbing Liu (HSRI), and Zhihong Feng (HSRI)

Presenter: Wei Miao (Purple Mountain Observatory)

Graphene has emerged as a promising platform for terahertz (THz) detection owing to its exceptionally weak electron–phonon coupling and ultralow electronic heat capacity. Here, we present the development of two distinct graphene-based detectors designed for THz imaging applications. The first detector employs a Johnson noise readout scheme, in which the electron temperature of graphene is inferred from the microwave Johnson noise emitted by hot electrons. This device achieves an electrical noise-equivalent power (NEP) of 15 fW/Hz⁰·⁵ and a dynamic range of 47 dB at 0.3 K. The second detector is based on a diffusive superconductor–graphene–superconductor (SGS) junction that exhibits a sharp resistive transition near 1.4 K arising from proximity-induced Josephson coupling. When read out using a dc superconducting quantum interference device (SQUID), the SGS Josephson detector demonstrates an optical NEP as low as 250–500 aW/Hz⁰·⁵ at 1.4 THz over the temperature range of 0.1–0.6 K. These results highlight the strong potential of graphene-based architectures for high-sensitivity THz imaging applications.