Effect of deposition rate of organic layer on electrical and optical characteristics of OLEDs

Abstract

We investigated the effects of deposition rate on the electrical characteristics and optical characteristics of organic light-emitting diodes(OLEDs) in the ITO(indiumtin-oxide) N,N'-diphenyl-N,N'-bis(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/ tris(8-hydroxyquinoline) aluminum (Alq(3))/Al device. We measured current density, luminous flux and luminance characteristics of devices by varying deposition rates of TPD and Alq3. It has been found that optimal deposition rate of TPD and Alq(3) was 1.5 angstrom/s. AFM measurement shows that surface roughness of the deposited film was the lowest when the deposition rate was 1.5 angstrom/s.