Overview & Objectives
In terms of solution-processed OLED displays, our objectives and research plans go well beyond current state-of-the-art. We aim to develop solution-processed highly efficient blue, green and red OLEDs free from noble metals, using device stack architectures fully compatible with multiple layer solution deposition.
Overview
Solution-processed OLEDs offer a cheaper fabrication technology, but the performance of these devices lags behind vacuum-deposited OLEDs, retarding their adoption; In fact, the first large-scale fabs have only recently come online and the first solution-processed OLED displays were only demonstrated in 2019 by JOLED. For SP-OLEDs to become widely adopted their performance must improve substantially. This requires both novel materials solutions and device solutions, underpinned by a fundamental understanding of the unique challenges facing the design and fabrication of these devices. We will produce new device models that address this issue through a dedicated and well-planned program that is based on targeted TADF emitter materials design, focusing on enhancing the photoluminescence quantum yield (PLQY) of the emitter, control of the orientation of its transition dipole moment to enhance light out-coupling, exploiting circularly polarized luminescence to obviate the need for external polarizers, producing narrowband emission using a combination of an exciton harvesting assistant dopant and a structurally rigid terminal emitter (so-called hyperfluorescence, HF, technique), in combination with a concerted evaluation of device fabrication methods (strategies for how to process an OLED stack with multiple layers and how to control charge balance in a solution-processed OLED, optimizing the device optics to achieve a microcavity effect), underpinned by the development of bespoke theoretical methods and tools that are fit for particular purpose to address the issues linked to solution-processed devices.
Objectives
We aim to develop and optimise families of solution-processable TADF-based OLED materials to produce devices with increased efficiency, high colour purity and enhanced stability, simultaneously. This will be achieved using the broad methodologies outlined below, focusing on the optoelectronic and physicochemical properties of the materials. Addressing these multifaceted and complex issues is of critical importance to the development of new solution processing techniques for the OLED industry to complement vacuum deposition techniques. This requires a cross-sectorial, multidisciplinary approach that is far beyond the capability of a single institution.
Find out more