A New Voltage-Programmed Pixel Structure Compensating for Threshold Voltage Shift of Organic Thin Film Transistor

A new voltage-programmed pixel circuit using soluble-processed organic thin film transistors (OTFTs) for an active matrix organic light emitting diode (AMOLED) is proposed. The proposed circuit is composed of four switching TFTs, one driving TFT and one storage capacitor, which is simulated by HSPICE. The proposed circuit can compensate for the non-uniformity of OLED current caused by the threshold voltage degradation of the OTFT. The simulation results demonstrate that the variation of OLED current corresponding to a 3V threshold voltage shift is decreased by 30% compared to the conventional 2-TFT pixel circuit.