By collecting heat energy from the environment and transforming it into electrical power, thermoelectric energy harvesters have the potential to provide energy for a variety of small electronic devices. Currently, the biggest challenge in developing thermoelectric energy harvesters is to make systems that are both powerful and efficient at the same time.
One material that scientists have experimented with for making thermoelectric energy harvesters is quantum dots, nano-sized crystals with semiconducting properties. Due to their sharp, discrete energy levels, quantum dots are good energy filters, which is an important property for thermoelectric devices.
In a new study published in the New Journal of Physics, a team of researchers from Switzerland, Spain, and the US has investigated a thermoelectric energy harvester design based on quantum wells. Although quantum wells are also made of semiconducting materials, they have different structures and energy-filtering properties than quantum dots.
"We have shown that quantum wells can be used as powerful and efficient energy harvesters," said coauthor Björn Sothmann, a physicist at the University of Geneva in Switzerland. "Compared to our previous proposal based on quantum dots, quantum wells are easier to fabricate and offer the potential to be operated at room temperature