Application of Phthalocyanine Derivatives as Hole Transporting Layer to Organic Light Emitting Devices

Abstract

We fabricated organic light emitting devices (OLEDs) with thermally stable metal tetra-aminophthalocyanine (MT4APc, where M is Co, Cu, or Zn) dispersed in poly(bisphenol A-co-4-nitrophthalic anhydride-co-1,3-phenylenediamine) (polyetherimide, PEI) or 2,2-bis(3,4-dicarboxy-phenyl) hexafluoroisopropane dianhydride-2,4,5,6-trimethyl-1,4-phenylene-diamine (6FDA-4MPDA) polyimide (PI) as a hole transporting layer (HTL). The relative efficiency of the MT4APc as a HTL was found to be in the order CuT4APc > CoT4APc ≈ TPD > ZnT4APc. It was found that the 6FDA-4MPDA PI as a matrix of HTL exhibited better hole transporting properties than PEI.