Multi-layered polymer light-emitting devices prepared by vapor deposition polymerization

Abstract

We present multi-layered light emitting devices based on conjugated polymer, poly(1,3,4-oxadiazole)s (PODs), prepared via solventfree process. To fabricate POD thin films, we adopted vapor deposition polymerization technique which involves co-deposition of two monomers and subsequent polycondensation reaction on substrate surface. High molecular weight POD films (Mn∼1000,000) are achieved by enhancing reactivity of the monomers. A bilayered device consisting a pair of POD layers which act as hole transporting/emitting and electron transporting layer generates blue-green electroluminescence peaked at 490nm. Devices consisting two layers of POD and small molecules are also fabricated and tested their device performance.