High-mobility ultrathin semiconducting films prepared by spin coating

The ability to deposit and tailor reliable semiconducting films ( with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics(1-3\). The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies ( such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication(4-11). Here we demonstrate a technique for spin coating ultrathin (similar to50 Angstrom), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS2-xSex films, which exhibit n-type transport, large current densities (> 10(5) A cm(-2)) and mobilities greater than 10 cm(2) V-1 s(-1) - an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells(12), thermoelectrics(13) and memory devices(14)).