AVS 65th International Symposium & Exhibition
    Thin Films Division Thursday Sessions
       Session TF-ThP

Paper TF-ThP39
Water-based Superconcentrated Electrolytes as Gate Dielectric for High-performance Solution-processed Oxide Thin Film Transistors

Thursday, October 25, 2018, 6:00 pm, Room Hall B

Session: Thin Film Poster Session
Presenter: Eun Goo Lee, Seoul National University, Republic of Korea
Authors: E.G. Lee, Seoul National University, Republic of Korea
K.-H. Lim, Seoul National University, Republic of Korea
J.T. Park, Seoul National University, Republic of Korea
S.-E. Lee, Seoul National University, Republic of Korea
J.H. Lee, Seoul National University, Republic of Korea
C.I. Im, Seoul National University, Republic of Korea
Y.S. Kim, Seoul National University, Republic of Korea
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Thin film transistors(TFTs) using oxide-based semiconductors have attracted much attention because of their large field-effect mobility, low process temperature and printing process. However, most TFTs require high operation voltage due to the low capacitance of the gate dielectric, which causes a large amount of power consumption. In order to realize electronic devices with miniaturization, light-weighting and flexibility, it is necessary to study high-k dielectrics materials which enable low operation voltage. To solve this problem, several research groups are studying various materials capable of forming an electrical double layer that lowers the operating voltage by accumulating ultra-high charge carriers at the semiconductor / dielectric interface. Herein, we propose water-based superconcentrated electrolytes films as gate dielectric materials to take advantage of the low cost, safety, environmentally friendly and high dielectric constant of water. By embedding water-based electrolytes in a cross-linking polymer network by photo irradiation, we fabricated robust and flexible free-standing films that were showed high capacitance values of 6.72 ± 0.16 uF/cm2 at 0.5 Hz. In addition, the low electrochemical stability window of conventional aqueous electrolytes has been extended from 1.2 V to 3 V, allowing stable TFT operation at ± 1 V. The device with aqueous route indium oxide semiconductor and water-based superconcentrated electrolytes film as a dielectric layer has demonstrated an excellent electrical characteristic, including a low operating voltage (≈1 V), small subthreshold swing voltage of 110 mV/dec and the linear mobility in excess of 30.7 ± 1.6 cm 2/V s at very low drain voltage (0.1 V). These findings will open the door to the use of environmentally friendly new dielectric materials for flexible and wearable devices with low-power consumption and high mobility.