Light emission from organic materials is not very common in everyday life. However, some living creatures, such as fire flies, emit light with amazingly high efficiencies. In comparison, mass-produced devices such as fluorescent lamps, incandescent light bulbs and television monitors – all of which are based on inorganic materials – are much less efficient. This is partly because organic materials can have extremely high quantum efficiencies for fluorescence – as high as 100% for fire flies. This suggests that organic materials could be used as the basis for a variety of highly efficient light-emitting devices.