Organic light emitting diodes (OLEDs) are promising candidates for the lighting revolution of the 21st century. Along with the ever-ongoing quest for stable emitter materials, strategies for improved out-coupling of light, cost- and energy efficient low temperature processing in particular ITO-free flexible transparent conductive electrodes need further attention to boost OLED technologies, because ITO fails to be mechanically stabile upon bending and the scarcity of indium translates into high and volatile prices. In this contribution we report on the design, realisation and characterization of a number of different low temperature processes for printed and spray coated TCE on flexible low cost substrates such as polyethylene terephthalate (PET), based on printed Ag and Cu nano-particle, particle-free and nano-wire inks. We will show that the attained highly ITO-free electrodes on PET show superior optical, electrical and mechanical performance as compared to PET/ITO samples.
|