12.1‐in. WXGA AMOLED display driven by InGaZnO thin‐film transistors

Abstract

Abstract— A full‐color 12.1‐in.WXGA active‐matrix organic‐light‐emitting‐diode (AMOLED) display was, for the first time, demonstrated using indium‐gallium‐zinc oxide (IGZO) thin‐film transistors (TFTs) as an active‐matrix backplane. It was found that the fabricated AMOLED display did not suffer from the well‐known pixel non‐uniformity in luminance, even though the simple structure consisting of two transistors and one capacitor was adopted as the unit pixel circuit, which was attributed to the amorphous nature of IGZO semiconductors. The n‐channel a‐IGZO TFTs exhibited a field‐effect mobility of 17 cm2/V‐sec, threshold voltage of 1.1 V, on/off ratio >109, and subthreshold gate swing of 0.28 V/dec. The AMOLED display with a‐IGZO TFT array is promising for large‐sized applications such as notebook PCs and HDTVs because the a‐IGZO semiconductor can be deposited on large glass substrates (larger than Gen 7) using the conventional sputtering system.

Material characteristics and applications of transparent amorphous oxide semiconductors

“…Samsung group joined this competition, reporting AM OLED displays [9][10][11], and now offer the world's largest AM-OLED at 12.1 inches [11,12], as well as a 15-inch liquid-crystal display (LCD) operating at 240 Hz [13], which was reported at the Society of Information Display meeting in April 2008.…”

Transparent Oxide Semiconductors: Fundamentals and Recent Progress

“…AM-LCD panel using a-IGZO backplane [56]. An excellent review article [7]on OLED panels using a TAOS-TFT backplane was published by a group from Samsung.…”

“…As a result, the Hall mobility exceeds >10 cm 2 (V s) À1 , which is comparable with those in the corresponding crystals and is larger by an order of magnitude than that in a-Si:H, notwithstanding that room temperature (RT) fabrication is easily possible by a conventional sputtering method on any type of substrate including plastics. These characteristics led to the realization of high performance TFTs fabricated on plastic substrates in 2004 [6], and serious studies are being performed by industry for the application of these TFT arrays as the driver backplane of organic LED displays and next generation liquid crystal displays [7]. The third advance was the extension of TCO candidate materials.…”

Effect of an Al2O3/TiO2 Passivation Layer on the Performance of Amorphous Zinc–Tin Oxide Thin-Film Transistors

“…This remarkable development of oxide TFTs has been enabled by enhancement of high-mobility ZnObased channel materials, resulting in a substantial amount of research in high-performance TFTs with oxide semiconductor active layers, for example InZnO (IZO), 1,2 ZnSnO (ZTO), 3,4 and InGaZnO (IGZO). [5][6][7] However, to achieve low-voltage consumption, improvements in subthreshold swing (SS) and field-effect mobility (l FE ) are still required to meet the demands of integrated peripheral circuits on glass substrates. Recently, LG Display released a 55-in full-high-definition (FHD) organic light-emitting diode (OLED) TV containing an IGZO oxide TFT active matrix (AM).…”