IMID 2022, Pusan, Korea
August 23 - August 26, 2022 (Tue. - Fri.), Bexco
Novel AMOLED Pixel Circuit Compensating for Variations in Sub-threshold Swing and Threshold Voltage of a-IGZO Thin-Film Transistors
Hyunwoo Kim, Yongchan Kim, and Hojin Lee
Abstract
Amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) have been employed for the backplane
of AMOLED displays because of high carrier mobility, good uniformity, and low off currenet. However, it is
inevitable to have variations in threshold voltage (VTH) and sub-threshold swing (S.S.) due to bias-stress during
display operations as well as the fabrication deviations. The VTH shift can be attributed to charge trapping in gate
dielectric and interface states of semiconductor materials while the S.S. variation can cause a problem of leakage
current that increases power consumption. Therefore, a circuit-level compensation method for deviation is required. In this paper, we have proposed a novel a-IGZO TFT pixel circuit which can compensate for the VTH and S.S.
variation of the drive TFT.
