a-InGaZnO Active-Matrix Organic LED Pixel Periodically Detecting Thin-Film Transistor Threshold Voltage Once for Multiple Frames

This letter proposes a new voltage-programmed amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) pixel circuit for active-matrix organic light-emitting diode (AMOLED) displays. The proposed circuit detects the VTH of the driving TFT only in a periodically executed compensation frame, allowing the other frames to perform only data input and emission for high-speed applications. An HSPICE model is also established based on the measured electrical characteristics of a fabricated a-IGZO TFT. The simulation results reveal that the proposed circuit can compensate for the degradation of the driving TFT and the OLED without external circuits. Moreover, the current error rates are <;6.32%, so the proposed circuit is effective for use in AMOLED displays.