After slight chemical de-doping, a conducting polymer can efficiently convert heat into electricity, reports a paper online this week in Nature Materials. The thermoelectric efficiency of the material approaches the values required for cooling and waste-heat-recovery applications.
Thermoelectric elements generate electrical power when their ends are held at different temperatures. The efficiency of this process depends on the ability of the base material to maintain an internal temperature gradient, determined by its thermal conductivity and its electrical conductivity. In many materials, such as most inorganic semiconductors, these properties cannot be changed independently.
Through careful chemical modification, Xavier Crispin and colleagues were able to optimize the electrical conductivity of a conducting polymer known as PEDOT without affecting its low thermal conductivity. The thermoelectric efficiency of their material approaches the values required for practical operation in cooling elements and power generators.