Researchers at Marie Curie-Skłodowska University, in Lublin, Poland have demonstrated the importance of thermoelectric effects in nanostructures. For about 200 years physicists have sought the efficient turning of heat into electricity in the field called thermoelectrics.

Scientists have long known that in conducting materials the flow of energy in the form of heat is also accompanied by a flow of electrons. What researchers haven’t known until recently is that it takes nanometric-scale systems for the flow of charge and heat to reach a level of efficiency that can’t be achieved with larger scale systems.

Barbara Szukiewicz and Karol Wysokiński from Marie Curie-Skłodowska University have demonstrated the not easily modeled importance of thermoelectric effects in nanostructures. Their paper has been published in The European Physical Journal B in the open access format.

Beginning in the 1990s, scientists have looked into developing efficient energy generation from nanostructures such as quantum dots. The quantum dots’ advantage is they display a greater energy conversion efficiency leading to the emergence of nanoscale thermoelectrics.

The research team evaluated the thermoelectric performance of models made of two quantum dots, which were coupled electrostatically, connected to two electrodes kept at a different temperature and a single quantum dot with two levels.

First, they used the theoretical approach based on approximations to calculate the so-called thermoelectric figure of merit, expected to be high for systems with high energy conversion efficiency. Then, they calculated the charge and heat fluxes as a means to define the efficiency of the system.

They found that the outcomes of the direct calculations giving the actual – as opposed to theoretical – performance of the system were less optimistic. For most parameters with an excellent performance, calculated predictions turned out to be surprisingly poor.

The findings reveal that effects that are not easily formalized using equations are important at the nanoscale. This, in turn, calls for new ways to optimize the structures before they can be used for nanoscale energy harvesting.

This is a fundamental research effort with quite surprising results. The research is showing perhaps why the flow of thermoelectric ideas aren’t getting any noticeable traction. It could very well aid in getting better equations into use which should go back to improving the research of others.

Its also very pleasing to see worthwhile basic research coming out of Poland. Good useful work ladies!


Comments

1 Comment so far

  1. Marc on May 19, 2015 4:43 AM

    Brian: Keep up the good work. Love you site. Also, could I beg for you to go hound the EMC2 guys for an update…. even if it’s bad news, I would like to know how they are progressing. Such and exciting project. But, they have been silent since the Naval labs renewed. Cheers! Marc

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