A compensation threshold voltage shift pixel circuit for active matrix organic light emitting diode

In this paper, we propose a new Voltage-programming pixel circuit using hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) for an active matrix organic light-emitting diode (AMOLED). The proposed a-Si:H TFT pixel circuit, which consists of four p-type switching TFTs, one n-type driving TFT, two additional control signals and one storage capacitor, successfully compensated the OLED current fluctuation caused by threshold voltage shift of a-Si:H TFT and the drop on the supply voltage, the propose pixel circuit has been verified by the simulation work using HSPICE software, the simulation result show that this pixel circuit has high immunity to the variation of a-Si:H TFT characteristics.