title: Ti-doped indium tin oxide thin films for transparent field-effect transistors: control of charge-carrier density and crystalline structure.
abstract: Indium tin oxide (ITO) films are representative transparent conducting oxide media for organic light-emitting diodes, liquid crystal displays, and solar cell applications. Extending the utility of ITO films from passive electrodes to active channel layers in transparent field-effect transistors (FETs), however, has been largely limited because of the materials' high carrier density (>1 × 10(20) cm(-3)), wide band gap, and polycrystalline structure. Here, we demonstrate that control over the cation composition in ITO-based oxide films via solid doping of titanium (Ti) can optimize the carrier concentration and suppress film crystallization. On 120 nm thick SiO(2)/Mo (200 nm)/glass substrates, transparent n-type FETs prepared with 4 at % Ti-doped ITO films and fabricated via the cosputtering of ITO and TiO(2) exhibited high electron mobilities of 13.4 cm(2) V(-1) s(-1), a low subthreshold gate swing of 0.25 V decade(-1), and a high I(on/)I(off) ratio of >1 × 10(8).
authors.affiliation: Department of Materials Science and Engineering, Inha University, Incheon 402-751, Korea.
authors.forename: Ji-In
authors.initials: JI
authors.lastname: Kim
authors.forename: Kwang Hwan
authors.initials: KH
authors.lastname: Ji
authors.forename: Mi
authors.initials: M
authors.lastname: Jang
authors.forename: Hoichang
authors.initials: H
authors.lastname: Yang
authors.forename: Rino
authors.initials: R
authors.lastname: Choi
authors.forename: Jae Kyeong
authors.initials: JK
authors.lastname: Jeong