Conjugated organic semiconductor materials open up new exciting 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 organic semiconductor optoelectronics group we seek to understand the physics of these remarkable materials and devices, with the aim of improving them.