In the year of 2000, the Nobel prize in chemistry was awarded to three professors, Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa, for their contributions to discovery and development of conducting polymers. Their works altered the previously-held idea that organic and polymer materials are electrically insulating. Instead, conjugated organic or polymeric materials can be conductors and semiconductors. Compared with traditional inorganic counterparts, organic conductors and semiconductors have advantages of excellent mechanical flexibility, easy processing, potentially low cost, recyclability and easy tuning of their optoelectronic properties by molecular tailoring. In the past years, various organic optoelectronic devices have been demonstrated, including organic light-emitting diodes (OLED), organic photovoltaics (OPV), organic photodiodes (OPD), organic field-effect transistors (OFET), organic energy storage devices, etc. OLEDs have become mature technology for displays and lighting. Other organic optoelectronic devices are still being researched for practical applications. Novel organic optoelectronic materials, physics, devices and applications are ripe for investigation and exploration for a more sustainable society.