Effect of annealing of polythiophene derivative for polymer light-emitting diodes

The nature of the interface between the light-emitting layer and the metal electrode is of importance in determining device performance. The heat treatment of the electroluminescence device can enhance the adhesion of the polymer on the electrode by reducing free volume or pores in the interface. The current-voltage-luminance characteristic of the device with heat treatment at various temperatures was investigated. The annealed device above glass transition temperature (T-g) showed the most efficient characteristics. The current density was increased about 20 times over that of the unannealed device. The light intensity was also increased dramatically by 40 times. (C) 2002 American Institute of Physics.