Nanowerk December 8, 2022 Previous heat engines based on quantum dots have used reservoirs of electrons at different temperatures. An international team of researchers (Japan, Germany) has fabricated a nanoscale ‘heat engine’ that uses a property of spin as the effective working medium. They confined electrons using electric fields generated at surface metal electrodes on a gallium arsenide surface. The device had two interlinked quantum dots and a built-in charge sensor to passively monitor what was going on within the double quantum dot. A third quantum dot was used to control the double quantum dot’s thermal environment. According to the […]
Tag Archives: Heat engine
A new heat engine with no moving parts is as efficient as a steam turbine
MIT News April 13. 2022 Thermophotovoltaics (TPVs) can enable approaches to energy storage and conversion that use higher temperature heat sources than the turbines. However, despite predictions that TPV efficiencies can exceed 50% the demonstrated efficiencies are still only as high as 32%. A team of researchers in the US (MIT, National Renewable Energy Laboratory) has fabricated TPV cells with efficiencies of more than 40% and experimentally demonstrated the efficiency of high-bandgap tandem TPV cells. The TPV cells comprising III–V materials with bandgaps between 1.0 and 1.4 eV are optimized for emitter temperatures of 1,900–2,400 °C. The cells exploit the concept […]