With nearly 90% of the world’s energy produced by heat engines burning fossil fuels, a vast amount of energy is wasted as an engine’s max efficiency is 40% and often less. The rest of the energy is lost as heat, which dissipates into the environment. A means to harvest this wasted energy has remain elusive, but a new solution is on the horizon: thermoelectric polymers. Thermoelectric polymers have a high conductivity which, when coupled with a p-type and n-type semiconductor, can convert heat into electricity, or electricity into heat, via the Seebeck effect. In addition to heat engines, organic thermoelectric polymers are ideal for solar energy due to their performance at lower temperatures and their low-cost production. By augmenting current systems with thermoelectric polymers, we can build cheaper and more sustainable energy for decades to come.

One challenge thermoelectric polymers face is the balance between high electrical conductivity and a high Seebeck coefficient. Both increase the efficiency of the polymer, but as the two are inter-related, raising one effects the other. This leads to the need to have precise control over the ratios of the two variables via doping. Spearheading this research is graduate student Michael Lu-Diaz.