This diagram illustrates how thermoelectric materials use differences in temperature to generate electricity. Image: Tianjun Liu.
This diagram illustrates how thermoelectric materials use differences in temperature to generate electricity. Image: Tianjun Liu.

Researchers at Queen Mary University of London in the UK have developed new thermoelectric materials that could provide a low-cost option for converting heat energy into electricity.

Materials known as halide perovskites have been proposed as affordable alternatives to existing thermoelectric materials, but research into their suitability for thermoelectric applications has so far been limited.

In this study, reported in a paper in Nature Communications, researchers conducted a series of experiments on thin films of the halide perovskite caesium tin iodide to test its ability at producing electrical current from heat. The researchers found they were able to improve the materials' thermoelectric properties through a combination of methods, including conducting partial oxidation and introducing additional elements into the material.

"For many years, halide perovskites have been suggested as promising thermoelectric materials," said Oliver Fenwick, a lecturer in materials science at Queen Mary University of London. But whilst simulations have suggested good thermoelectric properties, real experimental data hasn't met these expectations.

"In this study, we successfully used 'doping' techniques, where we intentionally introduce impurities into the material, to tweak and improve the thermoelectric properties of caesium tin iodide, opening up options for its use in thermoelectric applications," Fenwick explained.

Thermoelectric materials use temperature differences to generate electrical energy. They have been suggested as a promising sustainable approach to both energy production and recycling, as they can be used to convert waste heat into useful electricity. But current, widely used thermoelectric materials are costly to produce and process, which has limited the uptake of this green technology.

"With the heightened global awareness of climate change and realization that a number of renewable energy solutions will be needed to meet our energy demands, thermoelectric generators are now at the center stage in today's ‘green technology’ debate," said Fenwick.

"The thermoelectric materials we currently have are expensive, and some even contain toxic components. One of the largest growth areas for thermoelectric technology is for domestic, commercial or wearable applications, so there's a need to find cheaper, non-toxic materials that can also operate well at low temperatures, for these applications to be fully realized. Our research suggests the halide perovskites could, with some fine-tuning, fill this void."

This story is adapted from material from Queen Mary University of London, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.