High-mobility pentacene thin-film transistor by using LaxTa(1-x)Oy as gate dielectric

Chuan Yu Han, Wing Man Tang, Cheung Hoi Leung, Chi Ming Che, Pui To Lai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)


Pentacene organic thin-film transistors (OTFTs) using LaxTa (1-x)Oy as gate dielectric with different La contents (x = 0.227, 0.562, 0.764, 0.883) have been fabricated and compared with those using Ta oxide or La oxide. The OTFT with La 0.764Ta0.236Oy can achieve a carrier mobility of 1.21 cm2 V-1s-1s, which is about 40 times and two times higher than those of the devices using Ta oxide and La oxide, respectively. As supported by XPS, AFM and noise measurement, the reasons lie in that La incorporation can suppress the formation of oxygen vacancies in Ta oxide, and Ta content can alleviate the hygroscopicity of La oxide, resulting in more passivated and smoother dielectric surface and thus larger pentacene grains, which lead to higher carrier mobility.
Original languageEnglish
Pages (from-to)2499-2504
Number of pages6
JournalOrganic Electronics: physics, materials, applications
Issue number10
Publication statusPublished - 1 Jan 2014


  • High-κ dielectric
  • La incorporation
  • Organic thin-film transistor
  • Oxygen vacancy
  • TaLaO

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • General Chemistry
  • Condensed Matter Physics
  • Materials Chemistry
  • Electrical and Electronic Engineering


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