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

Abstract

Platinum telluride (PtTe 2 ), a member of metallic transition metal dichalcogenides, provides a new platform for investigating various properties such as type-II Dirac fermions, topological superconductivity, and wide-band photodetection. However, the study of PtTe 2 is largely limited to exfoliated flakes, and its direct synthesis remains challenging. Herein, we report the controllable synthesis of highly crystalline 2D PtTe 2 crystals with tunable morphology and thickness via chemical vapor deposition (CVD) growth on Au substrate. By adjusting Te amount and substrate temperature, anisotropic and isotropic growth modes of PtTe 2 were realized on the solid and molten Au substrates, respectively. The domain size of PtTe 2 crystal was achieved up to 30 μm, and its thickness can be tuned from 5.6 to 50 nm via controlling the growth time. Furthermore, a metal-PtTe 2 -metal structural device was fabricated to validate the wide-band terahertz (THz) photodetection from 0.04 to 0.3 THz at room temperature. Owing to the high crystallinity of PtTe 2 crystal, the photodetector acquires high responsivity (30-250 mA W -1 from 0.12 to 0.3 THz), fast response rate (rise time: 7 μs, decay time: 8 μs), and high-quality imaging ability. Our work demonstrates the feasibility for realistic exploitation of high-performing photodetection system at THz band based on the CVDgrown 2D Dirac semimetal materials.

Fast Photothermoelectric Response in CVD‐Grown PdSe2 Photodetectors with In‐Plane Anisotropy

“…Compared to other photocurrent generation mechanisms, that is, photogating effect and PD effect, the PTE effect can achieve ultra‐broadband spectral response, which is not limited by the bandgap. [ 40 ] Here, we investigated the photoresponse in a broadband wavelength regime (from 405 to 940 nm) working in zero bias at room temperature. The short‐circuit photocurrent responses of the PdSe 2 photodetector shows self‐powered broadband photodetection ability by switching the laser on/off every 5 s in Figure a, indicating grown‐PdSe 2 flake can achieve ultra‐broadband photodetection.…”

Polarization Sensitive Solar‐Blind Ultraviolet Photodetectors Based on Ultrawide Bandgap KNb3O8 Nanobelt with Fringe‐Like Atomic Lattice

“…[ 10–14 ] Taking the widely studied 2D materials as examples, such materials cover a vast range of bandgaps from the terahertz in bilayer graphene, the NIR and visible in numerous transition metal dichalcogenides to the ultraviolet in h‐BN. [ 15–18 ] However, most 2D semiconductors are not competent for solar‐blind UV detection due to their relatively small bandgap (<2.5 eV). [ 15 ] Although several 2D wide bandgap (up to 3.40 eV) semiconductors can be used to detect UV light, [ 19–21 ] the low detection capability and the poor wavelength selectivity in solar‐blind UV photodetection hinder their practical applications.…”

A Universally EDTA-Assisted Synthesis of Polytypic Bismuth Telluride Nanoplates with a Size-Dependent Enhancement of Tumor Radiosensitivity and Metabolism In Vivo

“…11-0553), 44 hexagonal phase 1T-PtTe 2 (PDF No. 18-0977), 53 hexagonal phase Cu 2 Te (PDF No. 10-0421), 54 and rhombohedral phase of Sb 2 Te 3 (PDF No.…”