Anisotropic ultrasensitive PdTe2-based phototransistor for room-temperature long-wavelength detection

摘要

Emergent topological Dirac semimetals afford fresh pathways for optoelectronics, although device implementation has been elusive to date. Specifically, palladium ditelluride (PdTesub2/sub) combines the capabilities provided by its peculiar band structure, with topologically protected electronic states, with advantages related to the occurrence of high-mobility charge carriers and ambient stability. Here, we demonstrate large photogalvanic effects with high anisotropy at terahertz frequency in PdTesub2/sub-based devices. A responsivity of 10 A/W and a noise-equivalent power lower than 2 pW/Hzsup0.5/sup are achieved at room temperature, validating the suitability of PdTesub2/sub-based devices for applications in photosensing, polarization-sensitive detection, and large-area fast imaging. Our findings open opportunities for exploring uncooled and sensitive photoelectronic devices based on topological semimetals, especially in the highly pursuit terahertz band.