High-Luminance Thin Film Electroluminescent Devices Using Monoclinic Y2O3 Phosphor Activated with Mn

A new Mn-activated yttria (Y2O3:Mn) phosphor with a high luminous efficiency was developed using monoclinic Y2O3 as the host material. The monoclinic Y2O3:Mn phosphor thin films were prepared on substrates at a temperature of below approximately 400°C and postannealed at a temperature of approximately 1020°C in Ar atmosphere. Luminances of 7440 and 538 cd/m2 and luminous efficiencies of 1.1 and 10.1 lm/W for yellow emission were obtained for a thin-film electroluminescent device fabricated using monoclinic Y2O3:Mn phosphor and driven at 1 kHz and 60 Hz, respectively.