Threshold voltage compensation 6T2C-pixel circuit design using OTFT for flexible display. (August 2020)

• Record Type: Journal Article
• Authors: Pal, Shagun; Kumar, Brijesh
• Is Part Of: Microelectronics journal. Volume 102(2020)
• Publication Date: 2020-08
• Subjects: Organic thin film transistor -- Organic light emitting diode -- Six-transistors-two capacitors (6T2C) pixel circuit design -- Threshold voltage compensation; Microelectronics -- Periodicals; Microélectronique -- Périodiques; Microelectronics; Electronic journals; Journals - contents and abstracts; Periodicals; 621.3805
• DOI: 10.1016/j.mejo.2020.104818
• Languages: English
• ISSNs: 0959-8324

Abstract

Abstract: In this paper, an internal-circuit-compensation technique is proposed to improve the threshold-variation in the pixel circuit design using OTFTs for Flexible-displays. This pixel circuit design consists of six-transistors and two-storage-capacitors (6T2C), wherein five-transistors are used as the switching elements and one-transistor is employed as driver. The proposed pixel-circuit is capable not only to compensate the threshold-variations of driving thin-film-transistors (TFTs) efficiently but also to overcome the issue of mobility-variation-degradations of the circuit caused by the large-current-error. Additionally, two-conventional-transistors-one capacitor (2T1C) based pixel-circuit is analyzed and compared with the proposed 6T2C pixel-circuit as well. The obtained results indicate that the average ​- ​value of the current-error-rate is of 6.3% as the threshold-voltage varies by ±0.03 ​V, which is much lower than that of the conventional-2T1C-pixel-circuit. The maximum OLED current of the proposed-pixel-circuit is 2.45 ​μA that can be efficiently used in the small-screen-displays. Furthermore, the proposed-circuitry is analyzed to reduce the impact of the mobility-variation on the performance of the OLED-current to improve the display-performance.