Design of a Threshold Voltage Insensitive 3T1C Pixel Circuit Using a-IGZO TFT for AMOLED Displays

In this paper, we present an innovative 3T1C (3-TFT, 1-Capacitor) pixel architecture for AMOLED displays. The circuit proposed is voltage-programmed and employs amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). The paper presents detailed and extensive analyses discussing the threshold voltage (V-TH) shift detection and neutralizing ability of the proposed circuit along with a comparison with other recent leading-edge pixel circuits. For a 2.5 mu A current, the error in I-OLED is 0.79%, whereas, for a 1 mu A current, the error is 2.27%. Even for a very small current of 50 nA, the error is limited to only 7.75%.