Semiconductor‐to‐metal transition in platinum dichalcogenides induced by niobium dichalcogenides

Abstract Metallizing 2D semiconductors is a crucial research area with significant applications, such as reducing the contact resistance at metal/2D semiconductor interfaces. This is a key challenge in the realization of next‐generation low‐power and high‐performance devices. While various methods exist for metallizing Mo‐ and W‐based 2D semiconductors like MoS 2 and WSe 2 , effective approaches for Pt‐based ones have been lacking. This study demonstrates that platinum dichalcogenides (PtX 2 , X = Se or Te) undergo a semiconductor‐to‐metal transition when grown on niobium dichalcogenides (NbX 2 , X = Se or Te). PtX 2 /NbX 2 heterostructures were fabricated using molecular beam epitaxy (MBE) and characterized by Raman spectra, scanning transmission electron microscopy (STEM) and scanning tunneling microscopy/spectroscopy (STM/STS). Raman spectra and STEM confirm the growth of 1T‐phase PtX 2 and 1H‐phase NbX 2 . Both 2D STS mapping and layer‐dependent STS show that regardless of their layer numbers, both pristine semiconducting PtSe 2 and PtTe 2 are converted to metallic forms when interfacing with NbSe 2 or NbTe 2 . Density functional theory (DFT) calculations suggest that the metallization of PtSe 2 on NbX 2 and PtTe 2 on NbTe 2 results from interfacial orbital hybridization, while for PtTe 2 on NbSe 2 , it is due to the strong p ‐doping effect caused by interfacial charge transfer. Our work provides an effective method for metallizing PtX 2 semiconductors, which may lead to significant applications such as reducing the contact resistance at metal electrode/2D semiconductor interfaces and developing devices like rectifiers, rectenna, and photodetectors based on 2D Schottky diodes. image