Organic light-emitting diodes (OLED) are playing a major role in information technology (IT) by providing the promise of further expanding the use of digital displays through making display fabrication technology lower in cost and higher in performance to replace liquid crystal displays (LCD). Due to various attractive features such as high contrast, high brightness, large color gamut and thin structure, various sized OLED displays from small-sized mobile phone display to large-sized TV display have already begun to be mass-produced
