Effects of Crystallinity of Hole Transport Layers on Organic Electroluminescent Device Performance

Abstract

The electrical and light-emitting behavior of organic electroluminescent (EL) cells consisting of an 8-hydroxyquinoline aluminum light-emitting layer and a copper phthalocyanine hole transport layer has been studied. Both layers were prepared by vacuum deposition. When the indium-tin-oxide (ITO) glass substrate was cooled to near the liquid N₂ temperature during the vacuum deposition of copper phthalocyanine, an amorphous layer was obtained, and the brightness of the cell was increased. It was confirmed that the light emission from the cell with an amorphous copper phthalocyanine layer was more uniform.