In the quest for more efficient energy solutions, researchers are constantly exploring new materials that can convert heat into electricity. A recent study published in the Journal of Materiomics, led by Yuqing Sun from the School of Physics at Shandong University, has shed light on a promising avenue for enhancing thermoelectric performance. The study focuses on quaternary chalcogenides, a class of materials known for their complex bonding environments that inherently limit heat conduction, making them ideal for thermoelectric applications.
The research team, led by Sun, delved into the intricacies of the bonding environment around selenium (Se) atoms in Cu2.1Mn0.9SnSe4, a compound known for its low lattice thermal conductivity. By strategically substituting manganese (Mn2+) with equimolar pairs of silver (Ag+) and indium (In3+), the researchers were able to fine-tune the bonding environment. This manipulation led to significant changes in bond lengths, angles, and strengths, particularly in the Ag-Se and In-Se bonds. “The increase in both bond length and angle, together with the reduction in bond strength, caused the doped samples to display strong anharmonicities,” Sun explained. This means the bonds vibrate in a more irregular manner, which is crucial for reducing thermal conductivity.
The impact of these changes was profound. The doped samples exhibited a notable reduction in lattice thermal conductivity (κL), reaching a minimum value of 0.55 W·m−1·K−1 at 673 K for the sample with x = 0.10. This reduction is a direct result of the weakened bond strength, which also lowers the sound velocities within the material. “The modification of the bonding environment around the anion is considered an effective means to optimize the thermoelectric performance of quaternary chalcogenides,” Sun stated.
The ultimate goal of such research is to improve the thermoelectric figure of merit, denoted as zT. In this study, the researchers achieved a zT value of 0.53 at 673 K for the x = 0.10 sample. This improvement highlights the potential of these materials for practical applications in the energy sector, where efficient heat-to-electricity conversion is crucial.
The findings published in the Journal of Materiomics, which translates to the Journal of Materials Science and Engineering, offer a glimpse into the future of thermoelectric materials. By understanding and manipulating the bonding environments, researchers can pave the way for more efficient and cost-effective energy solutions. This could revolutionize industries that rely on waste heat recovery, such as automotive, manufacturing, and power generation, making them more sustainable and energy-efficient.
As the world continues to seek cleaner and more efficient energy sources, research like Sun’s provides a beacon of hope. By fine-tuning the properties of materials at the atomic level, scientists are unlocking new possibilities for harnessing energy in ways that were previously thought impossible. The implications of this research extend far beyond the laboratory, promising to shape the future of energy technology and drive innovation in the construction and energy sectors.
