The effect of the molecular structure on the optoelectronic properties of a fluorophore for use in organic light-emitting diodes.

A novel yellow light-emitting material, (2Z)-3-[4,4"-bis(dimethylamino)-1,1':4',1"-terphenyl-2'-yl]-2-phenylacrylonitrile (BDAT-P), having the modified molecular structure from red fluorescent compound, (2Z, 2'Z)-3,3'-[4,4"-bis(dimethylamino)-1,1':4',1"-terphenyl-2',5'-diyl]bis(2-phenylacry-lonitrile) (ABCV-P), was synthesized in order to study the effect of the molecular structure on the optoelectronic properties of a light-emitting material. UV-visible absorption and photoluminescence (PL) emission peaks measured in various solvent systems were summarized in Table I. In the respective solvent system, the bathochromic shift of PL emission peak relative to the peak of UV-visible absorption was much larger for ABCV-P with two electron donor-acceptor pairs than for BDAT-P with one electron donor-acceptor pair. EL emission peaks of devices using BDAT-P and ABCV-P as the host emitters measured to be 573 and 613 nm, respectively. Commission Internationale de l'Eclairage (CIExy) coordinate of device using BDAT-P was measured to be (0.4855, 0.5021) at 7 V, which was correspond to the yellow color.