Most polymers, or plastics, are electrical insulators. However there is one class of polymers, known as 'conjugated' polymers which can conduct electricity. These materials are semiconductors, and open new directions in optoelectronics. They combine novel semiconducting electronic properties with the processing flexibility of polymers. When a voltage is applied to them, they emit light, providing an important new display technology that could give flat and even flexible displays. Semiconducting polymers can be used to make field effect transistors, solar cells, and even lasers. In the polymer optoelectronics group we seek to understand the physics of these remarkable materials and devices, with the aim of improving them. The research has both fundamental and applied aspects, and the main activities are: - optical amplifiers - wavelength scale microstructure - new materials - charge transport in LEDs - understanding the light emission process.