High-mobility ultrathin semiconducting films prepared by spin coating

• Published in: Nature (London) 2004-03, Vol.428 (6980), p.299-303
• Main Authors: Mitzi, David B., Kosbar, Laura L., Murray, Conal E., Copel, Matthew, Afzali, Ali
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Fabrication; Humanities and Social Sciences; letter; Low temperature; Low-field transport and mobility; piezoresistance; multidisciplinary; Physics; Science; Science (multidisciplinary); Semiconductors; Solar cells; Thin film coatings; Thin films
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature02389

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 , 2 , 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 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . Here we demonstrate a technique for spin coating ultrathin (∼50 Å), 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 SnS 2- x Se x 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 ).