Upscaling of Organic Light Emitting Devices: a focus on innovative materials, versatile printing techniques and state-of-the-art post-treatments

Abstract

Novel materials and processes are explored to bridge the gap between laboratory scale and industrial scale processing of Organic Light Emitting Diodes (OLEDs). Current laboratory deposition and post-treatment techniques are not well suited for industrial scale processing of OLEDs. These deposition and post-treatment techniques fail to be roll-to-roll compatible and/or are resource hungry. Furthermore, the current ‘defacto standard’ indium-tin-oxide transparent anode needs to be replaced by an indium free alternative. Microwave annealing of these organic (OLED) materials is investigated as alternative post-deposition annealing treatment. Ultrasonic spray coating is studied as deposition technique of the active layer in OLEDs. Boron doped Nano Crystalline Diamond with an embedded gold grid (BNCD:Au-grid) is explored as transparent anode for OLEDs. The results show that microwave annealing is a faster post-deposition annealing technique while preserving the electronic properties of these organic materials. It is also shown that ultrasonic spray coating is a viable roll-to-roll compatible deposition technique for the active layer of OLEDs. The indium – free BNCD:Au-grid anode shows comparable efficacies and an enhanced luminous flux compared to the reference ITO based OLED.