AUTHOR=Go David B. , Haase John R. , George Jeffrey , Mannhart Jochen , Wanke Robin , Nojeh Alireza , Nemanich Robert TITLE=Thermionic Energy Conversion in the Twenty-first Century: Advances and Opportunities for Space and Terrestrial Applications JOURNAL=Frontiers in Mechanical Engineering VOLUME=3 YEAR=2017 URL=https://www.frontiersin.org/journals/mechanical-engineering/articles/10.3389/fmech.2017.00013 DOI=10.3389/fmech.2017.00013 ISSN=2297-3079 ABSTRACT=

Thermionic energy conversion (TEC) is the direct conversion of heat into electricity by the mechanism of thermionic emission, the spontaneous ejection of hot electrons from a surface. Although the physical mechanism has been known for over a century, it has yet to be consistently realized in a manner practical for large-scale deployment. This perspective article provides an assessment of the potential of TEC systems for space and terrestrial applications in the twenty-first century, overviewing recent advances in the field and identifying key research challenges. Recent developments as well as persisting research needs in materials, device design, fundamental understanding, and testing and validation are discussed.