State Key Laboratory of Electronic Thin Films and Integrated Devices,School of Optoelectronic Information,University of Electronic Science and Technology of China,Chengdu 610054,China
The article describes a highly effective alternated red-emitting organic light-emitting diode(OLED), which uses 9,9-spirobifluoren-2-yl-diphenyl-phosphine oxide (SPPO1) with high triple state as the host and hole-blocking layer and Bis(1-phenyl-isoquinoline) (Acetylacetonato)iridium(III) (Ir(pig)2(acac)) as objected emitting materials. The energy of SPPO1 in the luminescent layer, is respectively transferred by a Frster or Dexter process to the single state or triple state of Ir(pig)2(acac) and then the device shows red light emitting. The improvements in OLED performance and the tunability of emitting light are realized through regulating the ratio of Ir(pig)2(acac).