Annealing effect of gold thin lms on the light output performances of organiclight emitting diodes

Abstract

Gold thin lms (GTFs) are transferred onto a nanostructured surface and their effects on the characteristicsof organic light emitting diodes (OLED) are investigated. GTF deposition is realized by the physical vapor depositiontechnique under high vacuum. Globose gold nanostructures are successfully generated by annealing GTFs at differ-ent temperatures. Atomic force microscopy reveals morphological changes affected by lm thicknesses and annealingtemperatures. In the tailored device architecture, GTFs, [poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) andpoly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene are used as a hole injection layer, a hole transport layer, andan emissive layer, respectively. The performances of the fabricated OLEDs are enhanced in the presence of gold nanos-tructures obtained by thermal annealing GTFs coated onto the anode electrode of the devices. GTF thickness of 4.0 nmand an annealing temperature of 500◦C yield a nearly 2.6 times increase in the light output of the OLEDs.