Achieving ultra-low contact barriers in MX2/SiH (M = Nb, Ta; X = S, Se) metal-semiconductor heterostructures: first-principles prediction.

Abstract

Minimizing the contact barriers at the interface, forming between two different two-dimensional metals and semiconductors, is essential for designing high-performance optoelectronic devices. In this work, we design different types of metal-semiconductor heterostructures by combining 2D metallic MX2 (M = Nb, Hf; X = S, Se) and 2D semiconductor SiH and investigate systematically their electronic properties and contact characteristics using first principles calculations. We find that all the MX2/SiH (M = Nb, Ta; X = S, Se) heterostructures are energetically stable, suggesting that they could potentially be synthesized in the future. Furthermore, the generation of the MX2/SiH metal-semiconductor heterostructures leads to the formation of the Schottky contact with ultra-low Schottky barriers of a few tens of meV. This finding suggests that all the 2D MX2 (M = Nb, Ta; X = S, Se) metals act as effective electrical contact 2D materials to contact with the SiH semiconductor, enabling electronic devices with high charge injection efficiency. Furthermore, the tunneling resistivity of all the MX2/SiH (M = Nb, Ta; X = S, Se) MSHs is low, confirming that they exhibit high electron injection efficiency. Our findings underscore fundamental insights for the design of high-performance multifunctional Schottky devices based on the metal-semiconductor MX2/SiH heterostructures with ultra-low contact barriers and high electron injection efficiency.