White lighting : an assessment of different organic, hybrid, non-conventional and theoretical methods

• Main Author: Angioni, Enrico
• Published: University of Strathclyde 2016
• Subjects: 547
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707287

During the last two decades, worldwide economic growth has highlighted the issue of new and more efficient lighting technologies. The swift development of new and high performing inorganic and organic emissive materials has brought to the market competitive and efficient solid state lighting (SSL) devices with promising performance features and efficiencies well beyond those of traditional artificial lighting. They are predicted to become the next generation of general illumination systems and researchers are working worldwide in order to improve device properties, cost and environmental impact of these technologies. The principal aim of this work is to develop new emissive materials that can be employed for lighting applications using different expedients. Furthermore, in order to do this, a deep understanding of the electronic processes and of the molecular interactions that are behind their properties is desired. In the first chapter, the fundamentals of organic electronic materials, with a particular focus on OLEDs, are described. The principles that are behind the production of white light using organic materials are discussed, with practical examples able to summarise the state of the art technologies explored currently. In the second chapter, novel emissive materials based on the under explored bis-benzothiadiazole (bBT) unit are presented. These have been successfully incorporated as down converters in simple hybrid inorganic-organic white LEDs and their performance studied. In chapter 3, four OLED devices that employ a novel benzothiadiazole (BT) derivative molecule as the single emissive layer are presented. The performances of the devices depended on the architecture chosen, and they achieved colour qualities similar to those of commercial fluorescent tubes. In chapter 4, a new way to make highly emissive materials has been explored, with two metal-organic frameworks (MOFs) and four porous organic polymers (POPs) synthesised and characterised. Finally, the role of non-covalent interactions in dictating constricted geometries have been explored in a novel class of 4,8-benzobisthiazole (BBT) materials in chapter 5.