First-Ever Reference Material for Measuring Conversion of Heat to Electrical Energy at High Temps

Standard Reference Material (SRM) 3452 enables, for the first time, instrument validation and interlaboratory data comparison to support the research, development, and production of materials and devices related to thermoelectric (thermal to electrical) energy conversion applications at high temperature (295 K to 900 K). The Seebeck coefficient is a transport property that quantifies the conversion of an applied temperature difference into a proportional voltage. Materials that exhibit a large Seebeck coefficient, in addition to high electrical conductivity and low thermal conductivity, are considered candidates for use in thermoelectric applications. These applications include solid-state waste heat recovery in automotive engines and in industrial manufacturing furnaces, power generation for spacecraft, the replacement of batteries in wearable and portable devices, and refrigeration for consumer products, optical components, and microelectronics. The waste heat recovery market is expected to be $66 billion/yr globally in 2021. Thermoelectric generator sales specifically have increased 3x in the last 4 years, but the discovery and commercialization of new and higher efficiency thermoelectric materials has been impeded by unreliable measurements, leading to erroneous breakthroughs. SRM 3452 is a bar-shaped artifact of p-type (boron-doped) polycrystalline silicon-germanium (Si80Ge20) with nominal dimensions  2.5 mm x 2.5 mm x 14.0 mm. SRM 3452 will complement SRM 3451 Low Temperature Seebeck Coefficient Standard (10 K to 390 K), released for purchase in 2011. Together, these two SRMs provide certified reference materials for Seebeck coefficient measurements over the temperature range 10 K to 900 K.