Magnetron sputtering deposited large-scale Weyl semimetal THz detector

Abstract

THz detectors are considered as a building block for a wide range of applications including THz imaging system as well as THz communication system. However, beset by low sensitivity, small effective detection area, high preparation cost and high noise equivalent power, further research still needs especially in high-performance and large-scale THz detectors. In order to fulfill this requirement, Weyl semimetal MoTe2 was chosen as the active layer due to its lower dark current and Weyl-point enhancement. Moreover, high-quality and large-scale THz MoTe2-based detectors were fabricated with an effective detection area of 1 mm × 6.3 mm by means of magnetron sputtering deposition method. With an external voltage applied, our device exhibits excellent surface plasmon polaritons effect for THz detection and demonstrates a photoresponse of 4 A/W and a noise equivalent power of 9.74 × 10-12 W Hz−1/2 under the illumination of 0.1 THz wave at room temperature. Our research paves the way to the fabrication of large-scale THz detectors, also proves that the Weyl semimetal can be an excellent candidate of high-performance material in long-wave detection.