Standardisation in thermoelectric transport properties measurements- The Cardiff NEDO laboratories and DLR Cologne program

L. Bertini¹, K. Billquist²,M. Christensen³, C. Gatti¹, L. Holmgren⁴, B.Iversen³, E. Mueller⁵, M. Muhammed², G.Noriega⁶, A. Palmqvist⁷, D. Platzek⁵, D.M.Rowe⁸, A. Saramat⁷, C. Stiewe⁵, M. Toprak²,S.G.K. Williams⁸, Y. Zhang²

¹Istituto di Scienze e TecnologieMolecolari (ISTM), Via Camillo Golgi 19, 20133 Milano, Italy

²RoyalInstitute of Technology, Materials Chemistry Division, SE-10044 Stockholm,Sweden

³Universityof Aarhus, Department of Chemistry, DK-8000 C Aarhus, Denmark

LEGELAB,SE-451 44 Uddevalla, Sweden

⁵GermanAerospace Center (DLR), Institute of Materials Research, D-51170 Cologne,Germany

⁶CIDETE Ingenieros SL, E-08800Vilanova (Barcelona), Spain

⁷ChalmersUniversity of Technology, Dept. Applied Surface Chemistry, Goteborg, Sweden

⁸NEDO Laboratory for ThermoelectricEngineering (NEDO), Cardiff, UK

The need for ensuring accurate and consistentexperimental data is crucial for the success of any materials developmentprogramme. A current European funded research project “NanoThermEl”combines the talents of several leading research centres from across Europe indeveloping improved thermoelectric materials with reduced thermal conductivity,based on nano-sized particles. An essential requirement in this programme isthe thermoelectric characterisation of new samples including Seebeckcoefficient, electrical conductivity, thermal conductivity and the resultingdimensionless figure-of-merit ZT over a wide temperature range. A considerablenumber of samples have to be evaluated throughout the project, this work beingdivided between two leading thermoelectric characterisation laboratories, NEDOCardiff and DLR Germany. The use of different measurement techniques, samplegeometrical requirements and equipment however meant that some form ofmeasurement standardisation was necessary between partners, ensuring thatmeaningful and comparative data would result. This paper describes how this wasachieved by defining suitable standardisation and round robin tests. Such testsare expected to encourage further such standardisation to be carried outbetween thermoelectric semiconductor research laboratories, thus increasingconfidence and traceability of published data. A proposal“SemiStand” has been recently submitted to the European Union withthe aim of providing funding to achieve this goal.