Thermionic emission energy distribution from nanocrystalline diamond films for direct thermal-electrical energy conversion applications

2009 ◽  
Vol 106 (4) ◽  
pp. 043716 ◽  
Author(s):  
Kishore Uppireddi ◽  
Tyler L. Westover ◽  
Timothy S. Fisher ◽  
Brad R. Weiner ◽  
Gerardo Morell
Keyword(s):  
Energy Distribution ◽  
Energy Conversion ◽  
Diamond Films ◽  
Thermionic Emission ◽  
Electrical Energy ◽  
Nanocrystalline Diamond ◽  
Emission Energy ◽  
Nanocrystalline Diamond Films

Vacuum Thermionic Energy Conversion Based on Nanocrystalline Diamond Films

2006 ◽  
Vol 48 ◽  
pp. 83-92
Author(s):  
F.A.M. Koeck ◽  
J.M. Garguillo ◽  
John R. Smith ◽  
Y.J. Tang ◽  
G.L. Bilbro ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Work Function ◽  
Diamond Films ◽  
Thermionic Emission ◽  
Nanocrystalline Diamond ◽  
Effective Work ◽  
Effective Work Function ◽  
Nanocrystalline Diamond Films ◽  
Thermionic Energy Conversion ◽  
Thermionic Energy

Vacuum thermionic energy conversion achieves direct conversion of heat into electrical energy. The process involves thermionic electron emission from a hot surface and collection of the electrons on a cold surface where the two surfaces are separated by a small vacuum gap. Results are presented which indicate that nanocrystalline diamond films could lead to highly efficient thermionic energy conversion at temperatures less that 700°C. A critical element of the process is obtaining a stable, low work function surface for thermionic emission. Results are presented which establish that N-doped diamond films with a negative electron affinity can exhibit a barrier to emission of less than 1.6 eV. Films can be deposited onto field enhancing structures to achieve an even lower effective work function. Alternatively, nanocrystalline diamond films prepared with S doping exhibit field enhanced thermionic emission and an effective work function of ~1.9 eV. The field enhanced structures can reduce the effect of space charge and allow a larger vacuum gap. The possibility of a low temperature nanocrystalline diamond based thermionic energy conversion system is presented.

Photo- and thermionic emission of MWPECVD nanocrystalline diamond films

2014 ◽  
Vol 320 ◽  
pp. 798-803 ◽  
Author(s):  
G. Cicala ◽  
V. Magaletti ◽  
A. Valentini ◽  
M.A. Nitti ◽  
A. Bellucci ◽  
...  
Keyword(s):  
Diamond Films ◽  
Thermionic Emission ◽  
Nanocrystalline Diamond ◽  
Nanocrystalline Diamond Films

On the Nature of Grain Boundaries in Nanocrystalline Diamond

MRS Bulletin ◽  
1998 ◽  
Vol 23 (9) ◽  
pp. 36-41 ◽  
Author(s):  
P. Keblinski ◽  
D. Wolf ◽  
F. Cleri ◽  
S.R. Phillpot ◽  
H. Gleiter
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Active Sites ◽  
Critical Role ◽  
Diamond Films ◽  
Structural Disorder ◽  
Nanocrystalline Diamond ◽  
High Wear Resistance ◽  
Atomic Structures ◽  
Nanocrystalline Diamond Films

The low-pressure synthesis of rather pure nanocrystalline diamond films from fullerene precursors suggests that for a small enough grain size the diamond structure may be energetically preferred over graphite. Because of the small grain size of typically about 15 nm in these films, a significant fraction of the carbon atoms is situated in the grain boundaries (GBs). The surprisingly high wear resistance of these films even after the substrate is removed and their high corrosion resistance suggest that the grains are strongly bonded. Grain-boundary carbon is also believed to be responsible for the absorption and scattering of light in these films, for their electrical conductivity, and for their electron-emission properties. In spite of all these indications of a critical role played by GB carbon in achieving the remarkable properties of nanocrystalline diamond films, to date the atomic structures of the GBs are essentially not known.It is well-known that the electronic and optical properties of polycrystalline silicon films are significantly affected by the presence of GBs. For example GBs can provide active sites for the recombination of electron-hole pairs in photovoltaic applications. Also, in electronic devices such as thin-film transistors, GBs are known to play an important role. Because of silicon's strong energetic preference for sp3 hybridization over other electronic configurations, the structural disorder in silicon GBs is accommodated by a distortion of the tetrahedral nearestneighbor bonds and in the extreme by the creation of dangling bonds—that is, of three-coordinated Si atoms each having one unsaturated, bound electron in an otherwise more or less tetrahedrally coordinated environment.

Improved adhesion, growth and maturation of human bone-derived cells on nanocrystalline diamond films

2008 ◽  
Vol 205 (9) ◽  
pp. 2146-2153 ◽  
Author(s):  
Milan Kopecek ◽  
Lucie Bacakova ◽  
Jiri Vacik ◽  
Frantisek Fendrych ◽  
Vladimir Vorlicek ◽  
...  
Keyword(s):  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Human Bone ◽  
Nanocrystalline Diamond Films

DNA attachment to nanocrystalline diamond films

2005 ◽  
Vol 202 (11) ◽  
pp. 2212-2216 ◽  
Author(s):  
S. Wenmackers ◽  
P. Christiaens ◽  
M. Daenen ◽  
K. Haenen ◽  
M. Nesládek ◽  
...  
Keyword(s):  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Nanocrystalline Diamond Films ◽  
Dna Attachment

Electrical properties of nitrogen incorporated nanocrystalline diamond films

2006 ◽  
Vol 15 (4-8) ◽  
pp. 626-630 ◽  
Author(s):  
K.L. Ma ◽  
W.J. Zhang ◽  
Y.S. Zou ◽  
Y.M. Chong ◽  
K.M. Leung ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Nanocrystalline Diamond Films
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