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With the present advances in electronics and rising functional demands, heat flux in electronic systems has increased significantly over the past decade.1 Data centers illustrate this, with roughly 1,200 in Europe and 5,000 in the United States.2 Reliability and power consumption depend on effective thermal management, yet active cooling remains mostly limited to liquid systems. The IRDS identifies thermal management as a major challenge, especially for power electronics.3
Thermoelectrics materials (TE) allow to build solid-state coolers without any moving part; when TE are CMOS-compatible or suitable for heterogenous integration, are key ingredients for sustainable computing and low-power Internet of Things applications. However, the required material properties differ depending on the target application: energy generation requires high ZT with low k to preserve the thermal gradient, while thermal management needs a decent k to exploit passive cooling as well.
Here, we present three examples on how TE allow to deal with these challenges. For each of them, we combine band-structure and electron–phonon coupling parameters with the Boltzmann Transport Equation to capture the transport physics and benchmark the results against experimental data.
- Half-Heusler compounds. These materials offer decent power output in the range of 1-10 mW/cm2 according to the operation temperature and DT. Although these figures look sufficient for remote sensing, Heusler alloys pay reliance on CRM. By exploiting complex compositions, keeping constant the electrons counts, e.g. NbFe0.67Cu0.33Sb0.5Sn0.5 or (Zn0.5Ti0.5)0.7V0.3Ni0.7Fe0.3Sb, we can ease the reliance on CRM.
- Advanced group IV CSiGeSn alloys. With the increasing heat flux in modern electronic systems, efficient and CMOS-compatible thermal management solutions are critically needed; fabrication-friendly TE materials enable AC operation, which can be exploited to address localized thermal hot-spots.4 Group-IV CSiGeSn alloys are promising thermoelectric materials due to the tunability of their transport coefficients through alloy composition.
- Nernst-Ettingshausen coefficient. A framework to estimate the NE coefficient for thermomagnetic applications is created, enabling device architectures based on a single, nearly intrinsic leg and avoiding the complexity of conventional p–n configurations.
1 A. Heydari et al., Appl. Therm. Eng. 239, 122122 (2024).
2 kpmg.com/ie/en/home/insights/2024/09/data-centres-in-europe-strategy.html.
3 IEEE, IRDS “Systems and Architectures” 2023.
4 Y. Liu et al., Nature Communications 15, 4275 (2024).
We acknowledge the CINECA award under the ISCRA initiative, for the availability of high-performance computing resources and support, and funding from MSCA action project ID 788465, EPSRC EP/X02346X/1, PRIN 2022 No. 2022XZ2ZM8, DFG projects No. 537127697, JST ASPIRE cooperation No. JPMJAP2413.
| Giovane Ricercatore (under 40) | No |
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