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

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 cm(2)/V-sec, threshold voltage of 1.1 V, on/off ratio > 10(9), 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.