Probing thermopower on the microscale

摘要: Thermoelectric (TE) generators provide electrical energy from direct conversion of heat by means the Seebeck effect; without moving parts, completely silent, and with negligible maintenance. As any other engine this exploits only a fraction Carnot efficiency (Rowe (ed.), CRC Handbook Thermoelectrics (CRC Press Inc., 1995), p. 19 1). The TE is linked to thermoelectric figure merit Z, which itself given basic material properties: Z = S2σ/κ. These are conductivity σ, thermal κ coefficient or thermopower S, known as factor proportionality between voltage output applied temperature difference in sample. A distinct sensitivity carrier concentration structural variations make control stabilisation very challenging complex structures since degradation diffusion, decomposition evaporation can be observed many cases during synthesis, operation even process characterisation semiconductors; particularly at elevated temperatures. Investigating compositional properties, stability, performance materials, consequently aiming understand their interaction, mainly methods like X-ray diffraction (XRD), energy-dispersive spectroscopy (EDX), scanning electron microscopy (SEM) integral dependent measurements particular transport properties used. Although materials research satisfies highest requirements on accuracy, above mentioned techniques not perfectly qualified investigate promising classes thoroughly. Against background usually article aims show, that an efficient becomes accessible for several questions use spatially resolved determination thermopower.