ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Vacuum thermionic energy conversion achieves direct conversion of heat into electricalenergy. The process involves thermionic electron emission from a hot surface and collection of theelectrons on a cold surface where the two surfaces are separated by a small vacuum gap. Resultsare presented which indicate that nanocrystalline diamond films could lead to highly efficientthermionic energy conversion at temperatures less that 700ºC. A critical element of the process isobtaining a stable, low work function surface for thermionic emission. Results are presented whichestablish that N-doped diamond films with a negative electron affinity can exhibit a barrier toemission of less than 1.6 eV. Films can be deposited onto field enhancing structures to achieve aneven lower effective work function. Alternatively, nanocrystalline diamond films prepared with Sdoping exhibit field enhanced thermionic emission and an effective work function of ~1.9 eV. Thefield enhanced structures can reduce the effect of space charge and allow a larger vacuum gap. Thepossibility of a low temperature nanocrystalline diamond based thermionic energy conversionsystem is presented
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.48.83.pdf
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