Dongbo Mi

Organic Electro-Phosphorescent Devices Using 2,4,6-Triphenothiazino-1,3,5-Triazine as a Host Material

A new 1,3,5-triazine derivative containing the phenothiazine moiety (PTZ-TRZ) has been synthesized for use as a host material of phosphorescent dye. The photoluminescence and electroluminescence properties of PTZ-TRZ were examined. We have fabricated phosphorescent organic light-emitting devices with tris(2-phenylpyridine) iridium [Ir(ppy)3] as a triplet emissive dopant in PTZ-TRZ host. The emission spectrum of the device exhibited a green emission from Ir(ppy)3, indicating that the energy transfer occurs from PTZ-TRZ to [Ir(ppy)3]. The device with 8% doping concentration of [Ir(ppy)3] in PTZ-TRZ showed external quantum efficiency of 3.72% and the peak luminance 6,870 cd/m2.

Synthesis and Light-Emitting Properties of New Polyfluorene Copolymers Containing 2,3-Diphenylfumaronitrile

A series of polyfluorene copolymers composed of 9,9-dioctylfluorene (DOF) and 2,3-diphenylfumaronitrile (DPFN), poly(DOF-co-DPFN)s, have been synthesized through a palladium (0)-catalyzed Suzuki coupling reaction, and their light-emitting properties have been investigated. The synthesized copolymers were soluble in common organic solvents such as chloroform, toluene, etc and formed a uniform thin film after spin coating. As the contents of 2,3-diphenylfumaronitrile in the copolymers increases, the optical band gaps of the copolymers decreased and HOMO energy levels were also slightly lowered. The absorption and PL emission spectra of the copolymers containing DPFN units shifted to longer wavelength region than those of poly(9,9-dioctylfluorene). Light-emitting devices were fabricated using these polymers as the emissive layers in an ITO/PEDOT:PSS/Polymer/Balq/LiF/Al configuration.