한국정보디스플레이학회:학술대회논문집

The Korean Infomation Display Society (한국정보디스플레이학회)
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Photofield-Effect in Amorphous InGaZnO TFTs

  • Fung, Tze-Ching (Dept. of Electrical Engineering and Computer Science, University of Michigan) ;
  • Chuang, Chiao-Shun (Dept. of Photonics & Display Institute, National Chiao Tung University) ;
  • Mullins, Barry G. (Dept. of Electrical Engineering and Computer Science, University of Michigan) ;
  • Nomura, Kenji (ERATO-SORST, JST, in Frontier Collaborative Research Center / Material and Structure Lab., Tokyo Institute of Technology) ;
  • Kamiya, Toshio (ERATO-SORST, JST, in Frontier Collaborative Research Center / Material and Structure Lab., Tokyo Institute of Technology) ;
  • Shieh, Han-Ping David (Dept. of Photonics & Display Institute, National Chiao Tung University) ;
  • Hosono, Hideo (ERATO-SORST, JST, in Frontier Collaborative Research Center / Material and Structure Lab., Tokyo Institute of Technology) ;
  • Kanicki, Jerzy (Dept. of Electrical Engineering and Computer Science, University of Michigan)
  • Published : 2008.10.13
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Abstract

We study the amorphous In-Ga-Zn-O thin-film transistors (TFTs) properties under monochromatic illumination ($\lambda=420nm$) with different intensity. TFT off-state drain current ($I_{DS_off}$) was found to increase with the light intensity while field effect mobility ($\mu_{eff}$) is almost unchanged; only small change was observed for sub-threshold swing (S). Due to photo-generated charge trapping, a negative threshold voltage ($V_{th}$) shift is also observed. The photofield-effect analysis suggests a highly efficient UV photocurrent conversion in a-IGZO TFT. Finally, a-IGZO mid-gap density-of-states (DOS) was extracted and is more than an order lower than reported value for a-Si:H, which can explain a good switching properties of the a-IGZO TFTs.

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