Penn State researchers have created a thermoelectric cooler that considerably improves cooling energy and effectivity for future high-power electronics. The gadget makes use of half-Heusler alloys and a novel annealing course of to yield greater cooling energy density and service mobility.
Revolutionary Thermoelectric Cooler for Subsequent-Technology Electronics
The event of next-generation electronics, set to function smaller but extra highly effective parts, requires modern cooling options. A newly designed thermoelectric cooler, the brainchild of Penn State scientists, notably improves cooling energy and effectivity in comparison with present business thermoelectric items. This improvement, the researchers consider, could possibly be instrumental in managing warmth in upcoming high-power electronics.
Mattress Poudel, analysis professor within the Division of Supplies Science and Engineering at Penn State, expressed optimism concerning the gadget’s future purposes. He stated, “Our new materials can present thermoelectric gadgets with very excessive cooling energy density. We have been capable of show that this new gadget can’t solely be aggressive by way of technoeconomic measures however outperform the present main thermoelectric cooling modules. The brand new era of electronics will profit from this improvement.”
Thermoelectric Coolers: Mechanism and Problem
Thermoelectric coolers perform by transferring warmth from one facet of the gadget to the opposite upon the appliance of electrical energy. This course of leads to a module with distinctly hot and cold sides. By inserting the chilly facet on heat-generating digital parts corresponding to laser diodes or microprocessors, the excess warmth will be pumped away, successfully controlling the temperature. Nevertheless, as these parts proceed to develop extra highly effective, thermoelectric coolers may even have to expel extra warmth.
The newly developed thermoelectric gadget demonstrated a 210% enhance in cooling energy density in comparison with the main business gadget, constructed from bismuth telluride. Moreover, it doubtlessly maintains the same coefficient of efficiency (COP), the ratio of helpful cooling to the power required, as reported within the journal Nature Communications.
Addressing Thermoelectric Cooling Challenges
Shashank Priya, vice president for research at the University of Minnesota and a co-author of the paper, shed light on the new device’s capabilities. He stated, “This solves two out of the three big challenges in making thermoelectric cooling devices. First, it can provide a high cooling power density with a high COP. This means a small amount of electricity can pump a lot of heat. Second, for a high-powered laser or applications that require a lot of localized heat to be removed from a small area, this can provide the optimum solution.”
Innovative Half-Heusler Material in the New Device
This novel device is constructed from a compound of half-Heusler alloys, a class of materials with distinctive properties promising for energy applications like thermoelectric devices. These materials offer considerable strength, thermal stability, and efficiency.
The researchers employed a special annealing process — which manipulates how materials are heated and cooled — enabling them to alter and regulate the material’s microstructure to remove defects. This method had not been previously used to fabricate half-Heusler thermoelectric materials.
The Annealing Process and Its Effects
The annealing process also substantially increased the material’s grain size, leading to fewer grain boundaries — regions in a material where crystallite structures meet and that reduce electrical or thermal conductivity.
Wenjie Li, assistant research professor in the Department of Materials Science and Engineering at Penn State, described this transformation: “In general, half-Heusler material has a very small grain size — nano-sized grain. Through this annealing process, we can control the grain growth from the nanoscale to the microscale — a difference of three orders of magnitude.”
Reducing the grain boundaries and other defects significantly enhanced the carrier mobility of the material, influencing how electrons can move through it, which resulted in a higher power factor. This power factor is especially crucial in electronics-cooling applications as it determines the maximum cooling power density.
High Thermal Management Applications and Future Implications
Li further explained the relevance of this advancement, stating, “For instance, in laser diode cooling, a significant amount of heat is generated in a very small area, and it must be maintained at a specific temperature for the optimal performance of the device. That’s where our technology can be applied. This has a bright future for local high thermal management.”
In addition to the high power factor, the materials produced the highest average figure of merit, or efficiency, of any half-Heusler material in the temperature range of 300 to 873 degrees Kelvin (80 to 1,111 degrees Fahrenheit.) This indicates a promising strategy for optimizing half-Heusler materials for near-room-temperature thermoelectric applications.
“As a country, we are investing a lot in the CHIPS and Science Act, and one problem might be how the microelectronics can handle high-power density as they get smaller and operate at higher power,” Poudel said. “This technology may be able to address some of these challenges.”
Reference: “Half-Heusler alloys as emerging high power density thermoelectric cooling materials” by Hangtian Zhu, Wenjie Li, Amin Nozariasbmarz, Na Liu, Yu Zhang, Shashank Priya and Bed Poudel, 6 June 2023, Nature Communications.
Also contributing were Amin Nozariasbmarz, assistant research professor and Na Liu and Yu Zhang, postdoctoral scholars, Penn State; and Hangtian Zhu, associate professor, Institute of Physics, Chinese Academy of Sciences, Beijing.
Researchers on the project were supported by grants from the Office of Defense Advanced Research Projects Agency, Office of Naval Research, U.S. Department of Energy, National Science Foundation and the Army Small Business Research Program.