Kumpei Oda

Inorganic EL devices with high‐performance blue phosphor and application to 34‐in. flat‐panel televisions

Abstract— A high-performance inorganic electroluminescence (EL) device has been successfully developed by using an EL structure with a thick dielectric layer (TDEL) and sputtered BaAl2S4:Eu blue phosphor. The luminance and efficacy were higher than 2300 cd/m2 and 2.5 lm/W at L60, 120 Hz, respectively. Furthermore, the luminance at L60, 1.2 kHz was more than 23,000 cd/m2. The phosphor layer has a single-phase and a highly oriented crystalline structure. The phosphor also shows high stability in air. A 34-in. high-definition television (HDTV) has been developed by combining a TDEL structure and color-conversion materials. The panels with an optimized color filter demonstrated a peak luminance of 350 cd/m2, a color gamut of more than 100% NTSC, and a wide viewing angle similar to that of plasma-display panels. The high reproducibility of the 34-in. panels using our pilot line has been confirmed.