Blue Organic Light-Emitting Diode Based on 1,2,3,4,5-Pentaphenyl-1- (8-Phenyl-1,7-Octadiynyl)Silole

A new silole derivative, 1,2,3,4,5-pentaphenyl-1-(8-phenyl-1,7-octadiynyl)silole, is synthesized, characterized, and used as the electron-transport/emission layers in organic light-emitting diodes. Blue emission at 492 nm is observed, with a maximum luminance of 10 460 cd/m/sup 2/ at 18 V. The respective maximum current and power efficiencies are 8.47 cd/A and 3.8lm/W. A triple-layer composite cathode was used, consisting of tris(8-hydroxy-quinolne)aluminum (Alq/sub 3/) lithium fluoride and aluminum. The dependence of emission efficiency on the thickness of TPD and Alq/sub 3/ is investigated and explained.