We report on an enhanced thermoelectric figure of merit ZT=sigmaS(2)T/lambda (where sigma is electrical conductivity, S is thermopower, T is absolute temperature, and lambda is thermal conductivity) for PbTe/PbSe0.20Te0.80 superlattices (SLs) and PbTe doping SLs due to a reduction of the thermal conductivity lambda parallel to the layer planes. Despite a small decrease of the power factors sigmaS(2) due to a reduction of sigma in these superlattices, the figure of merit is higher as compared to the corresponding bulk materials and reaches maximum values in the temperature range between 400 and 570 K

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The output signals of moulded Hall sensors show changes in offset and sensitivity when the devices are affected by changing temperatures. This behaviour is a result of the differences in the thermal expansion behaviour of the package materials and is also affected by their time-dependent, viscous material properties. The stresses affected to the sensor's sensitive layer will become effective via the piezo-Hall-effect as well as via piezo-resistivity which both change the sensitivity and the offset of the sensor's output voltage. For modelling the stress in the sensitive area correctly it is indispensable to consider the visco-elastic and the visco-plastic behaviour of the materials constituting the package. Especially for very accurate sensors or components operating in harsh environments these effects must be regarded. In this work we investigate the thermomechanical stresses, which are induced in the sensitive layer of a moulded Hall sensor during the assembly process, the investigations were based mainly on finiteelements-simulations.

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There is growing evidence for an enhancement of the thermoelectric figure of merit ZT in low dimensional structures. Thermoelectric nanostructures based on such materials could have a series of applications in sensors, coolers and low power energy conversion systems. Basic thermoelectric properties of Pb 1-x Sr x (Se,Te) epitaxial films grown by molecular beam epitaxy (MBE) on BaF 2 (111) substrates are presented. The structural quality is studied by high resolution X-ray diffraction (XRD). For multi quantum well (MQW) films XRD and atomic force microscopy (AFM) analysis show high structural perfection. Measurements of transport properties indicate an enhancement of the 2D-power factor σS 2 . High quality Bi 2 Te 3 -layers can also be prepared on BaF 2 (111) substrates using MBE. Multiple stacks of epitaxial IV-VI / V-VI layers are made. Growth characteristics were analyzed by RHEED, AFM, SEM and SIMS.