Enhanced Photoresponse in PdSe₂ via Local Plasma Treatment: Implication for Advanced Optoelectronic Devices

Phase transitions are crucial for tuning the physical properties of two-dimensional (2D) materials, as well as developing their high-performance device applications. Here, we reported the observation of a semiconducting-to-metallic-like phase transition in palladium diselenide (PdSe 2 ) by oxygen plasma treatment. Benefiting from the excellent compatibility of plasma treatment with the conventional microfabrication process, local phase transition in PdSe 2 allows for the realization. Such locally patterned metallic-like phase regions can serve as contacts in the corresponding transistors, which significantly reduce the Schottky barrier height, thus improving the device performance. Furthermore, we observe an improvement of photocurrent response when using the metallic-like regions as contacts. Our study provides a strategy to tune the properties as well as develop high-performance devices of PdSe 2, thereby extending the applications of plasma technology in 2D materials and their devices.