A high-brightness GaP green LED flat-panel device for character and TV display

High brightness green LED flat-panel display devices for character and TV displays have been developed by utilizing our automatic fabrication techniques. The picture elements of these devices are highly efficient GaP green LED´s having an average external efficiency of 0.23 percent at 12.5 A/cm²with encapsulation. There are 6144 (96 × 64, matrix) picture elements mounted on the alumina substrate for a type I device, 17 920 (160 × 112, matrix) for a type II, and 38 400 (320 × 240, zigzag) for a type III. A reflective glass sheet, which has holes into which the LED´s are fixed, is mounted on the alumina substrate in order to collect the light emitted from the LED´s and reflect it efficiently for type I and II devices, but not for a type III device. Brightness (luminance) is 70 ft . L (240 cd) at 0.5 mA/dot for a type I device, 40 ft . L (137 cd) at 0.3 mA/dot for a type II, and 40 ft . L (137 cd) at 0.5 mA/dot for a type III. In this paper, fabrication techniques, and structures and characteristics of flat-panel devices for character and TV displays are reported.