P-2: A New a-Si:H TFT Pixel Circuit Suppressing OLED Current Error Caused by the Hysteresis and Threshold Voltage Shift for Active Matrix Organic Light Emitting Diode

2005 ◽  
Vol 36 (1) ◽  
pp. 228 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Bong-Hyun You ◽  
Chang-Wook Han ◽  
Kwang-Sub Shin ◽  
Min-Koo Han
Keyword(s):  
Threshold Voltage ◽  
Light Emitting Diode ◽  
Threshold Voltage Shift ◽  
Voltage Shift ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Pixel Circuit ◽  
Current Error

A Novel Voltage-Programmed Pixel Circuit with Poly-Si TFTs for AMOLED Displays

2018 ◽  
Vol 27 (14) ◽  
pp. 1850221
Author(s):  
Zunkai Huang ◽  
Li Tian ◽  
Hui Wang ◽  
Songlin Feng
Keyword(s):  
Threshold Voltage ◽  
Light Emitting Diode ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Electrical Stress ◽  
Organic Light ◽  
Pixel Circuit ◽  
Display Performance

In this paper, we propose a novel voltage-programmed pixel circuit with polysilicon thin–flim transistors (poly-Si TFTs) for active matrix organic light-emitting diode (AMOLED) displays, which consists of one programming transistor, one driving transistor, four switching transistors and two storage capacitors, respectively. Specifically, the proposed pixel circuit is able to not only efficiently compensate for the threshold variations of TFTs, but also largely suppresses the electrical degradations of the devices caused by the long-term electrical stress. Moreover, the mobility variation of the driving transistor can be compensated as well. The simulation has been performed by HSPICE, and results indicate that the average values of nonuniformities are, respectively, 7.3% as the threshold-voltage varies by [Formula: see text][Formula: see text]V and 2.1%, as the mobility of the driving transistor varies by [Formula: see text]%, both of which are much lower than that of the conventional two-transistor and one-capacitor (2T1C) pixel. Furthermore, since the OLED is reverse-biased during the nonemission phases, the lifetime of OLED will be extended naturally. As a consequence, the proposed pixel circuit can substantially improve the display performance.

Backplane Requirements for Active Matrix Organic Light Emitting Diode Displays

2006 ◽  
Vol 910 ◽  
Author(s):  
Arokia Nathan ◽  
Denis Striakhilev ◽  
Reza Chaji ◽  
Shahin Ashtiani ◽  
Czang-Ho Lee ◽  
...  
Keyword(s):  
Threshold Voltage ◽  
Power Efficiency ◽  
Low Voltage ◽  
Crystalline Silicon ◽  
Light Emitting Diode ◽  
Threshold Voltage Shift ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

AbstractOrganic light emitting diode (OLED) displays are a serious competitor to liquid crystal displays in view of their superior picture quality, higher contrast, faster on/off response, thinner profile, and high power efficiency. For large area and/or high-resolution applications, an active matrix OLED (AMOLED) addressing scheme is vital. The active matrix backplane can be made with amorphous silicon (a-Si), polysilicon, or organic technology, all of which suffer from threshold voltage shift and/or mismatch problems, causing temporal or spatial variations in the OLED brightness. In addition, the efficiency of the OLED itself degrades over time. Despite these shortcomings, there has been considerable progress in development of AMOLED displays using circuit solutions engineered to provide stable and uniform brightness. Indeed the design of AMOLED pixel circuits, particularly in low-mobility TFT technologies such as a-Si, is challenging due to the stringent requirements of timing, current matching, and low voltage operation. While circuit solutions are necessary, they are not sufficient. Process improvements to enhance TFT performance are becoming inevitable. This paper will review pertinent material requirements of AMOLED backplanes along with design considerations that address pixel architecture, contact resistance, and more importantly, the threshold voltage stability and associated gate overdrive voltage. In particular, we address the question of whether conventional PECVD can be deployed for high mobility and high stability TFTs, and if micro-/nano-crystalline silicon could provide the solution.

An active-matrix organic light-emitting-diode pixel circuit for the compensation of I × R voltage drop in power line

2007 ◽  
Vol 15 (8) ◽  
pp. 541 ◽  
Author(s):  
Sang-Hoon Jung ◽  
Hong-Koo Lee ◽  
Tae-Joon Ahn ◽  
Chang-Yeon Kim ◽  
Chang-Dong Kim ◽  
...  
Keyword(s):  
Voltage Drop ◽  
Light Emitting Diode ◽  
Power Line ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Pixel Circuit
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