Mn-Activated Y2O3–GeO2 Phosphors for Thin-Film Electroluminescent Devices

Abstract

A new multicomponent oxide phosphor, Mn-activated Y₂O₃–GeO₂, is demonstrated to be very promising as the thin-film emitting layer for thin-film electroluminescent (TFEL) devices. High-luminance yellow emissions were obtained in TFEL devices using (Y₂O₃–GeO₂):Mn thin films prepared with a GeO₂ content of 0 to 100 mol%: 1756, 2500, 758 and 1629 cd/m² in 1-kHz-driven TFEL devices fabricated using Y₂O₃:Mn, Y₄GeO₈:Mn, Y₂GeO₅:Mn and Y₂Ge₂O₇:Mn phosphor thin films, i.e., a GeO₂ content of 0, 33, 50 or 67 mol%, respectively. In addition, high luminous efficiencies of 2.8, 3.4, 1.5 and 4.5 lm/W, respectively, were obtained in these TFEL devices using a driving voltage at 60 Hz.