Synthesis of 2D α‐GeTe Single Crystals and α‐GeTe/WSe₂ Heterostructures with Enhanced Electronic Performance

Abstract

Two-dimensional (2D) materials have attracted extensive attention due to their important prospects in electronics and optoelectronics. Synthesizing new 2D materials, characterizing their properties, and developing their applications are still important topics. Herein, the synthesis of α-GeTe nanoplates on different substrates via the chemical vapor deposition process and the systematical investigation of their structure and electrical properties, is reported. By controlling the synthesis temperature and carrier gas, α-GeTe nanoplates, with a lateral dimension up to 30 µm and a thickness down to 1.2 nm, which corresponds to the thickness of one unit cell, can be obtained on 2D WSe 2 substrate. Electrical transport studies show 2D α-GeTe nanoplates have an excellent conductivity (9.33 × 10 5 S m −1 ) and an extraordinary breakdown current density (6.1× 10 7 A cm −2 ). Compared with traditional WSe 2 transistors with deposited metal electrodes, the WSe 2 transistors with the metallic α-GeTe nanoplates as van der Waals metal electrodes achieved much better performance, such as higher on-state current (from 7.83 to 23.23 µA µm −1 ) and electron mobility (from 16.5 to 75.0 cm 2 V 1 S 1 ). This study demonstrates an effective pathway to achieve ultrathin 2D materials and provides an accessible strategy to improve the performance of 2D electronic devices.

Sb2Te3/MoS2 Van der Waals Junctions with High Thermal Stability and Low Contact Resistance

“…The ideal vdW gap between Sb 2 Te 3 and MoS 2 should be the key factor to unpin the Fermi-level [35][36][37][38] because no interfacial states or defects would exist in this region. Because of the ideal vdW junction formation Sb 2 Te 3 and MoS 2 , the small band offset can be maintained based on the theoretical band alignment, leading to enhanced device performance for 1L MoS 2 MOSFETs with Sb 2 Te 3 /W contacts.…”

Rational Manipulation of Active CNT Encapsulated Fe Doped NiCoP Nanoparticles In Situ Grown in Hierarchically Carbonized Wood for High‐Current‐Density Water Splitting

“…[47] The project-augmented wave (PAW) method was applied to describe the core-valence interaction. [48] The generalized gradient approximation (GGA) in the Perdew-Burke-Ernzerhof (PBE) functional was used to handle the exchange and correlation potential. [49] A cutoff energy of 450 eV with an energy convergence threshold of 1 × 10 −5 eV and force convergence criterion of 0.01 eV Å −1 was used.…”

van der Waals Contact for Two-Dimensional Transition Metal Dichalcogenides

“…To date, various TMD-based transistors with vdW contacts have been fabricated via vdW epitaxy, revealing improved device performance compared to those with conventional metal contacts. − For instance, heteroepitaxial stacking of metallic 1T′-WTe 2 on semiconducting WSe 2 as a vdW contact results in superior ambipolar FET properties, including higher on current, μ FET , and on–off ratio compared to FETs with Ti contacts . In particular, the ability to integrate specific metals with various semiconductors or specific semiconductors with various metals has facilitated the search for better M-S combinations.…”