Oxygen‐Assisted MOCVD Growth of Monolayer PtSe ₂ Films With Bandgap Opening for Semiconducting FET Channels

As device miniaturization approaches its physical limits, the performance enhancement of silicon electronics has become increasingly difficult, shifting attention toward 2D semiconductors as potential alternatives. Among these, monolayer platinum diselenide (PtSe 2 ) has garnered significant interest as a next‐generation channel material for nanoelectronics. Distinguished by its exceptional theoretical carrier mobility—six times higher than that of MoS 2— and remarkable air stability, monolayer PtSe 2 emerges as a promising candidate for advanced semiconductor applications. However, achieving uniform growth of high‐quality monolayer PtSe 2 presents challenges. In this study, we report the first successful growth of high‐quality monolayer PtSe 2 films using an optimized metal‐organic chemical vapor deposition (MOCVD) process. We confirmed the uniform growth of the monolayer films over an area of 1.5 cm × 1.5 cm through various optical analyses, proving superior controllability of precursor flow and growth rate. Oxygen was introduced during the growth process to effectively eliminate carbon impurities, resulting in a high‐quality film. Finally, we demonstrated an array‐level transistor employing the monolayer PtSe 2 as the channel, achieving low off‐current and a maximum I ON / I OFF ratio of 8.31 × 10 4 . We succeeded in growing an industrially applicable level of semiconducting PtSe 2 film, thereby highlighting the advantages of our growth method for future electronic applications.