Project R-13273

Optimizing carbon nanotube deposition as emissive layer in nearinfrared organic light emitting diodes applying ultrasonic spray coating techniques (Research)

OLEDs have become an integral part of life. Although visible OLEDs are widely spread, NIR OLEDs are still in the first stage of industrialization, requiring an increase in efficiency and a reduction in cost. Many strategies including using heavy metals, thermally activated delayed fluorescence help to achieve infrared emission. Disadvantages like vacuum fabrication, toxicity and low efficiency hinder their uptake. Combining innovative materials with up-to-date fabrication methods can tackle most of the challenges towards mass production of NIR OLEDs. In this project, we will employ non-toxic CNTs as emissive layer deposited with ultrasonic spray coating as a large area deposition technique. As the orientation of emissive dipoles has a significant impact on the OLED efficiency, we will investigate the CNT orientation with three approaches. A first approach is using ultrasonic spray coating only, where the slow evaporation of the solvents will lead to optimized alignment. Next, we add a screen to the spray process to achieve a more homogeneous wet layer and thus optimize evaporation. The final approach is applying an electric field to the CNTs after deposition. We hypothesize that a single technology or a combination of these will be effective for the alignment of CNTs having a direct impact on the efficiency of the NIR OLEDs. This can lead to a scientific breakthrough in the application of NIR OLEDs, with high potential in medical applications, due to the non-toxicity of CNT.

01 November 2022 - 31 October 2026