Transparent thin-film transistors with pentacene channel, AlOx gate, and NiOx electrodes

We report on the fabrication of pentacene-based transparent thin-film transistors (TTFT) that consist of NiOx, AlOx, and indium-tin-oxide (ITO) for the source-drain (S/D) electrode, gate dielectric, and gate electrode, respectively. The NiOx S/D electrodes of which the work function is well matched to that of pentacene were deposited on a 50-nm-thick pentacene channel by thermal evaporation of NiO powder and showed a moderately low but still effective transmittance of ∼25% in the visible range along with a good sheet resistance of ∼60Ω∕◻. The maximum saturation current of our pentacene-based TTFT was about 15μA at a gate bias of −40V showing a high field effect mobility of 0.9cm2∕Vs in the dark, and the on/off current ratio of our TTFT was about 5×105. It is concluded that jointly adopting NiOx for the S/D electrode and AlOx for gate dielectric realizes a high-quality pentacene-based TTFT.

[1]  A. Fujimori,et al.  Valence-band photoemission and optical absorption in nickel compounds , 1984 .

[2]  John L. Hutchison,et al.  The fabrication and characterization of nickel oxide films and their application as contacts to polymer/porous silicon electroluminescent devices , 1997 .

[3]  W. E. Meyer,et al.  Fabrication and characterisation of NiO/ZnO structures , 2004 .

[4]  Robert A. Street,et al.  Hole transport in polycrystalline pentacene transistors , 2002 .

[5]  S. Im,et al.  Photodetecting properties of ZnO-based thin-film transistors , 2003 .

[6]  S. Im,et al.  Correlation between photoelectric and optical absorption spectra of thermally evaporated pentacene films , 2004 .

[7]  Cherie R. Kagan,et al.  Thin-Film Transistors , 2007 .

[8]  T. Jackson,et al.  Pentacene organic thin-film transistors-molecular ordering and mobility , 1997, IEEE Electron Device Letters.

[9]  Satoshi Masuda,et al.  Transparent thin film transistors using ZnO as an active channel layer and their electrical properties , 2003 .

[10]  S. Im,et al.  Pentacene thin-film transistors with Al2O3+x gate dielectric films deposited on indium-tin-oxide glass , 2003 .

[11]  Hideo Hosono,et al.  Transparent Organic Thin‐Film Transistor with a Laterally Grown Non‐Planar Phthalocyanine Channel , 2004 .

[12]  Douglas A. Keszler,et al.  Spin-coated zinc oxide transparent transistors , 2003 .

[13]  S. Im,et al.  Fabrication of p-pentacene/n-Si organic photodiodes and characterization of their photoelectric properties , 2003 .

[14]  W. Göpel.  Initial steps of interface formation: Surface states and thermodynamics , 1979 .

[15]  Thomas N. Jackson,et al.  A reduced complexity process for organic thin film transistors , 2000 .

[16]  Benjamin J. Norris,et al.  ZnO-based transparent thin-film transistors , 2003 .

[17]  Hideo Hosono,et al.  Fabrication and photoresponse of a pn-heterojunction diode composed of transparent oxide semiconductors, p-NiO and n-ZnO , 2003 .

[18]  B. Wessels,et al.  Luminescence of heteroepitaxial zinc oxide , 1988 .

[19]  D. V. Lang,et al.  Field-effect transistor on pentacene single crystal , 2003 .

[20]  R. McLean,et al.  Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering , 2003 .