Chemical Synthesis and Integration of Highly Conductive PdTe₂  with Low-Dimensional Semiconductors for p-Type Transistors with Low Contact Barriers.

Abstract

Low-dimensional semiconductors provide promising ultrathin channels for constructing more-than-Moore devices. However, the prominent contact barriers at the semiconductor-metal electrodes interfaces greatly limit the performance of the obtained devices. Here, a chemical approach is developed for the construction of p-type field-effect transistors (FETs) with low contact barriers by achieving the simultaneous synthesis and integration of 2D PdTe₂ with various low-dimensional semiconductors. The 2D PdTe₂ synthesized through a quasi-liquid process exhibits high electrical conductivity (≈4.3 × 10⁶ S m^-1 ) and thermal conductivity (≈130 W m^-1 K^-1 ), superior to other transition metal dichalcogenides (TMDCs) and even higher than some metals. In addition, PdTe₂ electrodes with desired geometry can be synthesized directly on 2D MoTe₂ and other semiconductors to form high-performance p-type FETs without any further treatment. The chemically derived atomically ordered PdTe₂ -MoTe₂ interface results in significantly reduced contact barrier (65 vs 240 meV) and thus increases the performance of the obtained devices. This work demonstrates the great potential of 2D PdTe₂ as contact materials and also opens up a new avenue for the future device fabrication through the chemical construction and integration of 2D components.