Green Electroluminescent Emission from Substituted Polyacetylenes

Abstract

Electroluminescent (EL) cells fabricated utilizing monophenyl and diphenyl substituted polyacetylenes, i.e. poly(phenylacetylene) (PPA) and poly(diphenylacetylene) (PDPA) derivatives, as emitters are reported on. Green light emission from these polymers which are sandwiched between an ITO (indium-tin oxide) coated glass substrate and a Mg/Al cathode has been observed at a 6 V ITO forward bias. Among these polymers, poly[1-( p - n -butylphenyl)-2-phenylacetylene] (PDPA- n Bu) shows the highest efficiency for green light emission. The EL efficiency was improved by doping an electron transporting material, 2-(4-biphenylyl)-5-(4- t -butylphenyl)-1,3,4-oxadiazole (PBD), in these polymers, and a fivefold increase in EL efficiency was achieved.