High-Electron-Mobility and Air-Stable 2D Layered PtSe₂FETs

A layer-dependent semiconductor-to-semimetal evolution of 2D layered PtSe2was demonstrated, which is only dependent on the number of layers, instead of external effects (electrical and optical measurements, in combination with the DFT calculations, show distinct layer-dependent semiconductor-to-semimetal evolution of 2D layered PtSe2. Few-layer PtSe2device exhibits semiconducting behavior, and shows high room-temperature electron mobility in a back-gated configuration on SiO2/Si substrate. On the contrary, bulk PtSe2device demonstrates metallic-like behavior and has high conductivity. The widely tunable bandgap of PtSe2enables it to be expanded into near-infrared or even mid-infrared region, and effectively responds to the near-infrared optical stimuli with a high photoresponsivity. In addition, our PtSe2device also exhibits much better air-stability (over one year) than BP.