High carrier mobility epitaxially aligned PtSe2 films grown by one-zone selenization

Highlights: • Simple selenization method to grow large-area and thin PtSe₂ films. • Observation of thin-film interferences in X-ray diffraction proves thickness homogeneity and low film surface roughness. • Epitaxial ordering of PtSe₂ films on the c-plane sapphire. • High charge-carrier mobility exceeding 20 cm²/V.s observed for thin PtSe₂ films by four-probe Hall measurements. Few-layer PtSe₂ films are promising candidates for applications in high-speed electronics, spintronics and photodetectors. Reproducible fabrication of large-area highly crystalline films is, however, still a challenge. Here, we report the fabrication of epitaxially aligned PtSe₂ films using one-zone selenization of pre-sputtered platinum layers. We have studied the influence of growth conditions on structural and electrical properties of the films prepared from Pt layers with different initial thickness. The best results were obtained for the PtSe₂ layers grown at elevated temperatures (600 °C). The films exhibit signatures for a long-range in-plane ordering resembling an epitaxial growth. The charge carrier mobility determined by Hall-effect measurements is up to 24 cm²/V.s.