Infrared Nanoimaging of Surface Plasmons in Type-II Dirac Semimetal PtTe₂ Nanoribbons

Abstract

Topological Dirac semimetals made of two-dimensional transition-metal dichalcogenides (TMDCs) have attracted enormous interest for use in electronic and optoelectronic devices because of their electron transport properties. As van der Waals materials with a strong interlayer interaction, these semimetals are expected to support layer-dependent plasmonic polaritons yet to be revealed experimentally. Here, we demonstrate the apparent retardation and attenuation of mid-infrared (MIR) plasmonic waves in type-II Dirac semimetal platinum tellurium (PtTe2) nanoribbons and nanoflakes by near-field nanoimaging. The attenuated dispersion relations for the plasmonic modes in the PtTe2 nanoribbons (15–25 nm thick) extracted from the near-field standing-wave patterns are applied for the fitting of PtTe2 permittivity in the MIR regime, indicating that both free carriers and Dirac fermions are involved in MIR light–matter interaction in PtTe2. The annihilation of plasmonic modes in the ultrathin (<10 nm) PtTe2 is observed and analyzed, which manifests no near-field resonant pattern due to the intrinsic layer-dependent optoelectronic properties of PtTe2. These results could pave a potential wave for MIR photodetection and modulation with TMDC semimetals.

Controllable growth of type‐II Dirac semimetal PtTe2 atomic layer on Au substrate for sensitive room temperature terahertz photodetection

“…These novel properties of PtTe 2 provide tremendous opportunities for exploring its potential applications in electronics, optoelectronics, spintronics, and catalysis. [20][21][22][23][24] However, present studies on PtTe 2 are largely restricted to the mechanically exfoliated samples with low productivity, small domain size, and uncontrolled layer number. Chemical vapor deposition (CVD) growth has shown perfect potential in synthesizing 2D semiconducting TMDs materials in a well-controlled fashion.…”

Imaging and identification of point defects in PtTe2

“…While PtTe 2 has thus far been less heavily studied than some other members of the TMD family, such as MoS 2 [15][16][17] , it benefits from interesting properties. It has been shown to be a type-II Dirac semimetal 18 with high conductivity 19 , suggesting it may be suitable for applications in spintronics and quantum computing [20][21][22] . Recently, the potential use of PtTe 2 in a variety of different applications, such as electrocatalysis 11,23,24 , ultrafast photonics 25 , and terahertz photodetection 26 has been reported.…”

Antimony Nanopolyhedrons with Tunable Localized Surface Plasmon Resonances for Highly Effective Photoacoustic‐Imaging‐Guided Synergistic Photothermal/Immunotherapy

“…[ 13 ] In contrast, the study of semimetal nanomaterials in the field of PPTT has attracted little attention, and their potential application for PPTT remains unexplored. [ 14 ]…”