정공전달고분자와 유기형광염료의 혼합물 박막이 이용된 발광소자의 에너지 전달특성 연구

Abstract

Hole transporting polymer(poly[N-(p-diphenylamine)phenylmethacrylamide], PDPMA) was doped with nile red dye at various concentrations to study the influence of doping on the energy transfer during light emitting processes. Organic LEDs composed of ITO/blend(PDPMA-nile red)/Alq3/Al as well as thin films of blend(PDPMA-nile red)/Alq3 were manufactured for investigating photoluminescence, electroluminescence, and current-voltage characteristics. Atomic Force Microscopy was also used to observe surface morphology of the blend films. It was found that such doping significantly influences the efficiency of the energy transfer from the Alq3 layer to blended layer and the optical/electrical properties could be optimized by choosing the right concentration of the dye molecule. The results also showed a interesting correlation with the morphological aspect, i.e. the optimum luminescence at the concentration with the least surface roughness. When the concentration of nile red was 0.8 wt%, the maximum energy transfer could be achieved.