A Driving Method of Pixel Circuit Using a-IGZO TFT for Suppression of Threshold Voltage Shift in AMLED Displays

作者：Shin Woo Sul; Ahn Hyun A; Na Jun Seok; Hong Seong Kwan; Kwon Oh Kyong^*; Lee Ji Hun; Um Jea Gwang; Jang Jin; Kim Sung Hwan; Lee Jeong Soo

来源：IEEE Electron Device Letters, 2017, 38(6): 760-762.

DOI：10.1109/LED.2017.2699669

• mu LED
• compensation
• AMLED
• a-IGZO TFT
• stretched exponential model
• V-th shift suppression

A driving method of pixel circuit using amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) is proposed to improve the image quality of active matrix light-emitting diode displays. The proposed pixel circuit employs a diode-connected structure to compensate for variation in threshold voltage (V-th) of the a-IGZO TFT. In addition, the proposed driving method adopts negative bias annealing to suppress the V-th shift. The annealing time is optimized based on the experimental observation of the minimum V-th shift. After a stress time of 30 000 s, the measurement results showthat the (Vth) shift is reducedby 29.6%, using an optimized annealing time of 5% of one frame time. In addition, the maximum deviation in the emission current using the proposed driving method wasmeasured to be less than 4.32% after a stress time of 30 000 s.

• 出版日期2017-6