Influence of high energy ion irradiation on the field emission characteristics of CVD diamond films

Author(s):  
P.M. Koinkar ◽  
R.S. Khairnar ◽  
S.A. Khan ◽  
R.P. Gupta ◽  
D.K. Avasthi ◽  
...  
2001 ◽  
Author(s):  
S. H. Shin ◽  
T. S. Fisher ◽  
D. G. Walker ◽  
A. M. Strauss ◽  
W. P. Kang ◽  
...  

Abstract This work examines the electron field emission characteristics of polycrystalline diamond films at high temperatures. Diamond is an excellent material as a field emitter because its high mechanical hardness and chemical inertness enable robust reliability. Diamond is also a wide-band gap semiconductor, increasing the probability for selective emission of higher-energy electrons. In recent years, considerable interest has developed in energy conversion applications of polycrystalline diamond films. However, little work has been considered for the field emission characteristics of diamond at elevated temperatures. The motivation behind this study involves direct energy conversion applications in power generation systems, where high temperatures exist. N-doped polycrystalline diamond films were grown by plasma-enhanced chemical-vapor deposition (PECVD). To investigate the effect of increased temperatures on field emission, current-voltage measurements were taken from the same diamond film at varying temperatures. Results from these measurements indicate a decrease in the turn-on voltage with increasing temperature. Further analysis of the temperature dependency of diamond was achieved through the parameter estimation of the effective emitting area, field enhancement factor, and work function. These results suggest that high-energy electrons are responsible for improved emission at high temperature. The resulting possibilities for direct energy conversion via diamond field emission are considered and discussed.


2006 ◽  
Vol 48 ◽  
pp. 103-112 ◽  
Author(s):  
Claudio Manfredotti

CVD diamond films have reached in recent years superlative improvements in their “ detector grade “ quality, with a time derivative which was never registered for other similar frontier materials. The basic properties of high quality CVD diamond films make them very interesting for a wide range of radiation detectors : they provide fast signals with very low leakage currents, they are very radiation resistant, they have excellent thermal properties and they can be manufactured as free-standing detectors. The recent availability of single crystal CVD diamond samples of extreme good quality, suitable thickness and surface area has opened new application fields in nuclear detection and dosimetry, such as, for instance, hadron therapy and neutron spectrometry in fusion reactors. At the same time, strip and pixel detectors of unprecedented performances have been successfully realized and exploited in the framework of high energy physics experiments. The paper will review the more recent history of CVD diamond nuclear detectors with respect to material quality, with a particular emphasis on epitaxial single crystals diamond, and the achievements in terms of applications in some different fields.


2019 ◽  
Vol 807 ◽  
pp. 82-86
Author(s):  
Shu Yi Wei ◽  
Shi Jin Liu ◽  
Xiu Xia Zhang ◽  
Li Xin Guo

In this paper, nanodiamond films (NDF) were prepared on glass substrate by screen printing with nanodiamond. The NDF was printed with two layers and treated with different surface treatments.The field emission model of nanodiamond thin film was established. Field Emission of different Ratio was studyed. The mechanism by which the field emission characteristics of nanocrystalline diamond films are improved was analyzed.


1996 ◽  
Vol 424 ◽  
Author(s):  
J. Y. Shim ◽  
E. J. Chi ◽  
S. J. Rho ◽  
H. K. Baik

ABSTRACTThe field emission characteristics of the Si emitters and the diamond coated Si emitters are investigated. The Fowler-Nordheim plots of the two types of Si emitters show linear slopes. It means that the I-V characteristics follow the Fowler-Nordheim relation. Field emission for the two types of diamond coated Si emitters exhibits significant enhancement both in turn-on voltage and total emission current. The Raman spectrum shows that the high intensity graphite peak is observed with diamond peak and thereby large amounts of graphite may be included in the diamond grain boundary. It seems to be thought that the graphite participates in the low field emission. However, further investigations are needed to understand whether the graphite may enhance the emission characteristics of diamond or not.


2000 ◽  
Vol 621 ◽  
Author(s):  
F.A.M. Köck ◽  
J.M. Garguilo ◽  
B. Brown ◽  
R.J. Nemanich

ABSTRACTImaging of field emission and photoemission from diamond surfaces is accomplished with a high resolution photo-electron emission microscope (PEEM). Measurements obtained as a function of sample temperature up to 1000°C display thermionic field emission images (TFEEM). The system can also record the emission current versus applied voltage. N-doped diamond films have been produced by MPCVD with a N/C gas phase ratio of 48. The surfaces display uniform emission in PEEM at all temperatures. No FEEM images are detectable below 500°C. At ∼680°C the T-FEEM and PEEM images are nearly identical in intensity and uniformity. This is to be contrasted with other carbon based cold cathodes in which the emission is observed from only a low density of highly emitting sites. The I/V measurements obtained from the N-doped films in the T-FEEM configuration show a component that depends linearly on voltage at low fields. At higher fields, an approximately exponential dependence is observed. At low temperatures employed (<700°C), the results indicate a thermionic component to the emitted current.


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