Final Report Summary - EXCITON (Advanced Measurement and Control of Exciton Diffusion for Next Generation Organic Semiconductor Optoelectronics)
Organic semiconductors are remarkable plastic-like materials that combine novel semiconducting electronic properties with simple processing and fabrication. Their properties, such as colour of light emission can be tuned by changing the chemical structure and they can be used to make light-emitting diodes, solar cells and lasers. A distinctive feature of the physics of these materials is that when they absorb light they form a strongly bound exciton (electron-hole pair). Excitons can also emit light which can be useful for making displays and lighting, and also provides a window on the physics of the material. The purpose of the project was to advance understanding of the physics of organic optoelectronic materials, and excitons in particular. It has developed measurements of exciton diffusion and compared them to understand the best way of measuring this process which is very important in the operation or devices such as solar cells. It then used these measurement techniques to show how exciton diffusion is affected by the structure of the organic semiconductors. These insights were then used to develop ways of controlling exciton diffusion to enhance the performance of organic optoelectronic devices.