Title :
A new a-Si:H TFT pixel circuit compensating the threshold voltage shift of a-Si:H TFT and OLED for active matrix OLED
Author :
Lee, Jae-Hoon ; Kim, Ji-Hoon ; Han, Min-Koo
Author_Institution :
Sch. of Electr. Eng., Seoul Nat. Univ., South Korea
Abstract :
We propose a new hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) pixel circuit for an active matrix organic light-emitting diode (AMOLED) employing a voltage programming. The proposed a-Si:H TFT pixel circuit, which consists of five switching TFTs, one driving TFT, and one capacitor, successfully minimizes a decrease of OLED current caused by threshold voltage degradation of a-Si:H TFT and OLED. Our experimental results, based on the bias-temperature stress, exhibit that the output current for OLED is decreased by 7% in the proposed pixel, while it is decreased by 28% in the conventional 2-TFT pixel.
Keywords :
amorphous semiconductors; organic light emitting diodes; silicon compounds; switching circuits; thin film transistors; Si:H; a-Si:H TFT pixel circuit; active matrix OLED; active matrix organic light-emitting diode; driving TFT; hydrogenated amorphous silicon thin-film transistor pixel circuit; switching TFT; threshold voltage shift compensation; voltage programming; Active matrix organic light emitting diodes; Amorphous silicon; Anodes; Organic light emitting diodes; Stress; Switched capacitor circuits; Switches; Thermal degradation; Thin film transistors; Threshold voltage; Active matrix organic light-emitting diode (AMOLED); amorphous silicon thin-film transistor (a-Si:H TFT) pixel; degradation;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.859674
