Controlled Doping of Wafer-Scale PtSe₂ Films for Device Application

Semiconductive transition metal dichalcogenides (TMDs) have been considered as next generation semiconductors, but to date most device investigations are still based on microscale exfoliation with a low yield. Wafer scale growth of TMDs has been reported but effective doping approaches remain challenging due to their atomically thick nature. This work reports the synthesis of wafer-scale continuous few-layer PtSe₂ films with effective doping in a controllable manner. Chemical component analyses confirm that both n-doping and p-doping can be effectively modulated through a controlled selenization process. The electrical properties of PtSe₂ films have been systematically studied by fabricating top-gated field effect transistors (FETs). The device current on/off ratio is optimized in two-layer PtSe₂ FETs, and four-terminal configuration displays a reasonably high effective field effect mobility (14 and 15 cm² V⁻¹ s⁻¹ for p-type and n-type FETs, respectively) with a nearly symmetric p-type and n-type performance. Temperature dependent measurement reveals that the variable range hopping is dominant at low temperatures. To further establish feasible application based on controllable doping of PtSe₂, a logic inverter and vertically stacked p–n junction arrays are demonstrated. These results validate that PtSe₂ is a promising candidate among the family of TMDs for future functional electronic applications.