Dependence of the performance of the organic electroluminescent devices upon the deposition rate of organic thin films

Typical organic electroluminescent (EL) devices with triphenyldiamine derivative (TPD) and tris-(8-hydroxyquinoline) aluminum (Alq3) as the hole transport layer and electron transport layer, respectively, have been fabricated. The EL properties as a function of the deposition rate of the organic materials were investigated. It was found that a TPD deposition rate of around 0.2–0.3 nm/s is the optimum for the maximum luminous efficiency. The optimum deposition rate of Alq3 is 0.3–0.4 nm/s.