Ultrasensitive and Self‐Powered Terahertz Detection Driven by Nodal‐Line Dirac Fermions and Van der Waals Architecture

Abstract

Abstract Terahertz detection has been highly sought to open a range of cutting‐edge applications in biomedical, high‐speed communications, astronomy, security screening, and military surveillance. Nonetheless, these ideal prospects are hindered by the difficulties in photodetection featuring self‐powered operation at room temperature. Here, this challenge is addressed for the first time by synthesizing the high‐quality ZrGeSe with extraordinary quantum properties of Dirac nodal‐line semimetal. Benefiting from its high mobility and gapless nature, a metal‐ZrGeSe‐metal photodetector with broken mirror symmetry allows for a high‐efficiency photoelectric conversion assisted by the photo‐thermoelectric effect. The designed architecture features ultrahigh sensitivity, excellent ambient stability, and an efficient rectified signal even above 0.26 THz. Maximum responsivity larger than 0.11 A W−1, response time of 8.3 µs, noise equivalent power (NEP) less than 0.15 nW Hz−1/2, and demonstrative imaging application are all achieved. The superb performances with a lower dark current and NEP less than 15 pW Hz−1/2 are validated through integrating the van der Waals heterostructure. These results open up an appealing perspective to explore the nontrivial topology of Dirac nodal‐line semimetal by devising the peculiar device geometry that allows for a novel roadmap to address targeted terahertz application requirements.

Keywords

• nodal‐line semimetals
• photo‐thermoelectric effect
• terahertz photodetector
• ZrGeSe single crystals