PtTe2-based terahertz photodetector integrated with an interdigital antenna

Abstract

Two-dimensional materials such as graphene and black phosphorus have attracted considerable attention owing to their peculiar properties and unique applications, serve also as potential candidates for terahertz (THz) photodetection. Recent works have shown that the responsivity and sensitivity of photodetectors have been improved largely. However, there are still a few bottlenecks imposed by the fundamental limits of optical properties that impede further improvement of THz photodetection. With the continuous exploration of two-dimensional materials, especially the topological quantum states of the Dirac semimetals, which possesses uniquely non-linear optical effects, chiral anomaly and other quantization phenomena, provide a new platform for the study of fast and efficient THz photodetection. In this work, we experimentally demonstrated THz photodetectors based on Dirac semimetal-PtTe2 integrated with an interdigital antenna, which gives rise to high responsivity and fast response time in the meantime at room temperature. The achieved photocurrent responsivity is over 62 mA/W (0.12 THz) in the self-powered mode, with the noise equivalent power (NEP) is less than 60 pW/Hz0.5 (0.12 THz), and the performance has been significantly improved by applying finite voltage. Our results provide a new approach for developing high-performance THz photodetectors based on type-II Dirac semimetals.