High Mobility 2D Palladium Diselenide Field-Effect Transistors with Tunable Ambipolar Characteristics

Due to the intriguing optical and electronic properties, 2D materials have attracted a lot of interest for the electronic and optoelectronic applications. Identifying new promising 2D materials will be rewarding toward the development of next generation 2D electronics. Here, palladium diselenide (PdSe₂ ), a noble-transition metal dichalcogenide (TMDC), is introduced as a promising high mobility 2D material into the fast growing 2D community. Field-effect transistors (FETs) based on ultrathin PdSe₂ show intrinsic ambipolar characteristic. The polarity of the FET can be tuned. After vacuum annealing, the authors find PdSe₂ to exhibit electron-dominated transport with high mobility (µ_{e (max)} = 216 cm² V^-1 s^-1 ) and on/off ratio up to 10³ . Hole-dominated-transport PdSe₂ can be obtained by molecular doping using F₄ -TCNQ. This pioneer work on PdSe₂ will spark interests in the less explored regime of noble-TMDCs.