Kilian Bartholomé

Thermoelectric Modules Based on Half-Heusler Materials Produced in Large Quantities

Half-Heusler (HH) compounds are some of the most promising candidates among the medium-temperature thermoelectric materials being investigated for automotive and industrial waste heat recovery applications. For n- as well as p-type material, peak ZT values larger than one have been published recently, and first modules have been built. The next step to facilitate the industrialization of thermoelectric module production is upscaling of material synthesis. In this paper, the latest results of the thermoelectric properties of HH compounds produced in kg batches are presented and compared with values published in the literature. The performance of modules built from these materials is analyzed with respect to power output and long-term stability of the material and electrical contacts.

A Simple Sb2Te3 Back-Contact Process for CdTe Solar Cells

CdTe solar technology has proved to be a cost-efficient solution for energy production. Formation of the back contact is an important and critical step in preparing high-efficiency, stable CdTe solar cells. In this paper we report a simple CdTe solar cell (Sb2Te3) back contact-formation process. The CdS and CdTe layers were deposited by close-space sublimation. After CdCl2 annealing treatment, the CdTe surface was etched by use of a mixture of nitric and phosphoric acids to obtain a Te-rich surface. Elemental Sb was sputtered on the etched surface and successive post-annealing treatment induced Sb2Te3 alloy formation. Structural characterization by x-ray diffraction analysis confirmed formation of the Sb2Te3 phase. The performance of solar cells with nanoalloyed Sb2Te3 back contacts was comparable with that of reference solar cells prepared with sputtered Sb2Te3 back contact from a compound sputter target.

Reproducibility and Reliability in Manufacturing New High-Temperature Thermoelectric Modules

What is thermoelectrics? [1] - Thermoelectrics refers to the direct conversion of an electrical current flow into a heat flow as well as the heat flow into a current flow – thermoelectrics works in both ways.

Energieautarke Sensorik im Flugzeug

Zusammenfassung Der Einsatz energieautarker Sensorik bietet die Möglichkeit, wartungsfrei Sensoren über einen sehr langen Zeitraum an unzugänglichen Orten zu betreiben. Durch den Einsatz thermoelektrischer Generatoren wird die Verwendung energieautarker Systeme überall da ermöglicht, wo Temperaturgradienten mit wenigen Kelvin existieren. In diesem Artikel wird der Einsatz eines durch Thermogeneratoren versorgten energieautarken Systems für den Einsatz im Flugzeug vorgestellt und die Minimierung thermischer Widerstände als wesentlicher Punkt für eine maximale Leistungsausbeute diskutiert. Abstract The use of energy-autarkic sensors provides the ability to operate maintenance-free sensors over a long period of time in inaccessible places. Due to the use of thermoelectric generators, energy-autarkic systems can be applied everywhere where temperature gradients of a few degrees Kelvin exist. In this article, the application of an energy-autarkic systems in aircrafts powerd by thermoelectric generators is presented and the minimization of thermal resistances as a key point for maximum power output is discussed.