All-amorphous-oxide transparent, flexible thin-film transistors. Efficacy of bilayer gate dielectrics

Jun Liu, D. Bruce Buchholz, Jonathan W. Hennek, Robert P.H. Chang, Antonio Facchetti, Tobin J. Marks

Research output: Contribution to journalArticle

72 Citations (Scopus)

Abstract

Optically transparent and mechanically flexible thin-film transistors (TF-TFTs) composed exclusively of amorphous metal oxide films are fabricated on plastic substrates by combining an amorphous Ta2O5/ SiOx bilayer transparent oxide insulator (TOI) gate dielectric with an amorphous zinc-indium-tin oxide (a-ZITO) transparent oxide semiconductor (TOS) channel and a-ZITO transparent oxide conductor (TOC) electrodes. The bilayer gate dielectric is fabricated by the post-cross-linking of vapor-deposited hexachlorodisiloxane-derived films to form thin SiOx layers (v-SiOx) on amorphous Ta2O5 (a-Ta 2O5) films grown by ion-assisted deposition at room temperature. The a-Ta2O5/v-SiOx bilayer TOI dielectric integrates the large capacitance of the high dielectric constant a-Ta2O5 layer with the excellent dielectric/semiconductor interfacial compatibility of the v-SiOx layer in a-ZITO TOS-based TF-TFTs. These all-amorphous-oxide TF-TFTs, having a channel length and width of 100 and 2000 μm, respectively, perform far better than a-Ta 2O5-only devices and exhibit saturation-regime field-effect mobilities of ∼20 cm2/V·s, on-currents >10-4 A, and current on-off ratios >105. These TFTs operate at low voltages (∼4.0 V) and exhibit good visible-region optical transparency and excellent mechanical flexibility.

Original languageEnglish
Pages (from-to)11934-11942
Number of pages9
JournalJournal of the American Chemical Society
Volume132
Issue number34
DOIs
Publication statusPublished - Sep 1 2010

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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