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Title: Role of oxygen vacancies on the bias illumination stress stability of solution-processed zinc tin oxide thin film transistors

Solution-processed ultra-thin (∼3 nm) zinc tin oxide (ZTO) thin film transistors (TFTs) with a mobility of 8 cm{sup 2}/Vs are obtained with post spin-coating annealing at only 350 °C. The effect of light illumination (at wavelengths of 405 nm or 532 nm) on the stability of TFT transfer characteristics under various gate bias stress conditions (zero, positive, and negative) is investigated. It is found that the ΔV{sub th} (V{sub th}{sup stress} {sup 3400} {sup s − stress} {sup 0} {sup s}) window is significantly positive when ZTO TFTs are under positive bias stress (PBS, ΔV{sub th} = 9.98 V) and positive bias illumination stress (λ = 405 nm and ΔV{sub th} = 6.96 V), but ΔV{sub th} is slightly negative under only light illumination stress (λ = 405 nm and ΔV{sub th} = −2.02 V) or negative bias stress (ΔV{sub th} = −2.27 V). However, the ΔV{sub th} of ZTO TFT under negative bias illumination stress is substantial, and it will efficiently recover the ΔV{sub th} caused by PBS. The result is attributed to the photo-ionization and subsequent transition of electronic states of oxygen vacancies (i.e., V{sub o}, V{sub o}{sup +}, and V{sub o}{sup ++}) in ZTO. A detailed mechanism is discussed to better understand the bias stress stability of solution processed ZTO TFTs.
Authors:
;  [1] ;  [2]
  1. Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)
  2. Department of Materials Science, National University of Tainan, Tainan 700, Taiwan (China)
Publication Date:
OSTI Identifier:
22311108
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; CARRIER MOBILITY; ILLUMINANCE; OXYGEN; SIMULATION; SPIN-ON COATING; STABILITY; STRESSES; THIN FILMS; TIN OXIDES; TRANSISTORS; VACANCIES; VISIBLE RADIATION; WAVELENGTHS; ZINC; ZINC OXIDES