Izvestiya of Saratov University.

Physics

ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


For citation:

Yafarov R. K., Nefedov D. V., Storublev A. V. Vacuum-plasma processes at extreme field emission in diamond electron sources. Izvestiya of Sarat. Univ. Physics. , 2021, vol. 21, iss. 1, pp. 69-79. DOI: 10.18500/1817-3020-2021-21-1-69-79

This is an open access article distributed under the terms of Creative Commons Attribution 4.0 International License (CC-BY 4.0).
Published online: 
31.03.2021
Full text:
(downloads: 16)
Language: 
Russian
Article type: 
Article
UDC: 
537.533.2

Vacuum-plasma processes at extreme field emission in diamond electron sources

Autors: 
Yafarov Ravil' Kiashshafovich, Saratov State University
Nefedov Denis Vladimirovich, Saratov Branch of Kotel’nikov Institute of Radio Engineering and Electronics of the Russian Academy of Sciences
Storublev Anton Vyacheslavovich, Saratov State University
Abstract: 

Background and Objectives: The use of high-current field electron sources that satisfy various circuitry requirements as a part of electronic devices for various purposes suggests the possibility of matching their operation modes with the operating characteristics of the devices, as well as high reproducibility of emission parameters, stability and the necessary resource of reliability and durability. The stability and durability of field electron sources are extremely sensitive to the changes in the geometry of emission centers and to the state of their surface, which undergoes various destructive influences during operation. These changes are especially important in the case of high-current field-emission cathodes, which, as a rule, work under conditions of technical vacuum and high electric field intensities. The aim of the work was to study the possibility of creating field sources of electrons based on thin-film planar-end nanodiamond-graphite structures that satisfy various circuit requirements, as well as to study fundamental factors that lead to a change in their I–V characteristics and limit the maximum value of their field emission currents, stability and durability of high-current field emission. Materials and Methods: Emission structures were made of carbon films deposited in a microwave plasma of a low pressure gas discharge. The surface resistance of the films was 120 kOhm/□ and 1.2 mOhm/□. In the first type of emission structure, diamond-graphite films were mechanically separated into two parts. One part of the film was the cathode, the second served as the anode. Measurement of field emission characteristics in vacuum (2–4)·10-3 Pa. Between the cathode and the anode, voltage pulses with a duration of 10 μs and an amplitude of 0 to 3000 V were applied. In the second type of emission structure, field emission was carried out from the end face of a diamond-graphite film deposited on a polycor substrate. Field emission-voltage characteristics were measured in constant electric fields. Determination of the elemental composition of the surfaces of field emission structures after electrical tests was carried out using an energy dispersive microanalysis system. Results: It is shown that the steepness of the current-voltage characteristics, as well as the stability and durability in extreme operating conditions of high-current field electron sources based on film diamond-graphite nanocomposites, is determined by their surface resistance. Electron field sources based on low-resistance diamond-graphite structures, in comparison with high-resistance, have a high slope of the I–V characteristic, a lower threshold for the field intensity at the beginning of field emission, and the maximum field emission current is achieved at a lower electric field strength. The range of operating voltages providing the same maximum field emission current is many times higher for high-impedance electron sources than for low-impedance ones. The various nature of vacuum-plasma processes is established for extreme field emission in diamond-graphite electron sources with different surface resistance. In the case of lowresistance diamond-graphite composite film structures under extreme operating conditions of high-current planar-face autoemission structures, the main reasons for the instability of the emission and destruction parameters are the appearance of electrothermal breakdowns at the cathode of the “grid” characteristic of thin dielectric coatings during a sliding surface electric discharge. In the case of high-resistance diamond-graphite film structures, there is no branched network of electrothermal electrical breakdowns. In this case, as well as for high-current end field emission structures, the main nature of destruction under extreme operating conditions is erosion of the cathode part of the film. Erosion is caused by the processes of explosive electron emission, which is carried out from the nanodiamond emission centers of the composite carbon film structure with the appearance of a cathode plasma plume and the graphite component of the cathode material is sprayed onto the anode and into the interelectrode gap. Conclusion: The results can be used to predict the durability and stability of high-current field electron sources based on diamond-graphite film structures depending on their design, electrophysical characteristics, and vacuum operating conditions.

Reference: 
  1. Jun Zhang, Dian Zhanga, Yuwei Fan, Juntao He, Xingjun Ge, Xiaoping Zhang, Jinchuan Ju, Tao Xun. Progress in narrowband high-power microwave sources featured. Physics of Plasmas, 2020, vol. 27, pp. 010501. DOI: https://doi.org/10.1063/1.5126271
  2. Mittal G., Lahiri I. Recent progress in nanostructured next-generation field emission devices. J. Phys. D: Appl. Phys., 2014, vol. 47, pp. 323001. DOI: https://doi.org/10.1088/0022-3727/47/32/323001
  3. Fursey G. N., Polyakov M. A., Cantonistov A. A., Yafyasov A. M., Pavlov B. S., Bozhevolnov V. B. Autoelectronic and explosive emission from graphene-like structures. Technical Physics, 2013, vol. 83, iss. 6, pp. 71–77 (in Russian).
  4. Panda K., Hyeok J. J., Park J. Y., Sankaran K. J., Balakrishnan S., Lin I. N. Nanoscale investigation of enhanced electron field emission for silver ion implanted/ post-annealed ultrananocrystalline diamond films. Sci. Reports, 2017, vol. 7, pp. 16325. DOI: https://doi.org/10.1038/s41598-017-16395-1
  5. Sobaszek M., Siuzdak K., Ryl J., Sawczak M., Gupta S., Carrizosa S. B., Ficek M., Dec B., Darowicki K., Bogdanowicz R. Diamond Phase (sp3-C) Rich BoronDoped Carbon Nanowalls (sp2-C): Physicochemical and Electrochemical Properties. J. Phys. Chem. C, 2017, vol. 121, no. 38, pp. 20821. DOI: https://doi.org/10.1021/acs.jpcc.7b06365
  6. Yafarov R. K., Novikov P. E., Eremin V. P., Kochnev D. O. Investigation of the possibility of creating an field emission cathode for a non-incised magnetron based on a diamond graphite nanocomposite. Voprosyi yelektrotekhnologii [Questions of Electrotechnology], 2018, no. 2, pp. 62–71 (in Russian).
  7. Gulyaev Yu. V., Aban’shin N. P., Gorfinkel’ B. I., Morev S. P., Rezchikov A. F., Sinitsyn N. I., Yakunin A. N. New solutions for designing promising devices based on low-voltage field emission from carbon nanostructures. Technical Physics Letters, 2013, vol. 39, pp. 525‒528. DOI: https://doi.org/10.1134/S1063785013060035
  8. Yafarov R. K., Shanygin V. Ya., Nefedov D. V. Diamondgraphite nanocomposite for high-current field emission of electrons. Doklady VI Vserossiyskoy mikrovolnovoy konferentsii [Papers of the VI All-Russian Microwave Conference]. Moscow, 2018, pp. 142‒146 (in Russian).
  9. Yafarov R. K., Shanygin V. Y., Nefedov D. V. Carbon film nanocomposite for high-current field sources of electrons. Izvestiya of Saratov University. New Series. Series: Physics, 2019, vol. 19, iss. 1, pp. 68–75 (in Russian). DOI: https://doi.org/10.18500/1817-3020-2019-19-1-68-75
  10. Ye Hua, Hong Wan, Xingyu Chen, Bin Chen, Ping Wu, Shuxin Bai. Influence of Surface Microstructures on Explosive Electron Emission Properties for Graphite Cathodes. IEEE Transactions on Plasma Science, 2017, vol. 45, iss. 6, pp. 959‒968. DOI: https://doi.org/10.1109/TPS.2017.2703139
  11. Filip V., Filip L. D., Hei Wong. Review on peculiar issues of field emission in vacuum nanoelectronic devices. Solid-State Electronics, 2017, vol. 138, pp. 3–15. DOI: https://doi.org/10.1016/j.sse.2017.09.010
  12. Amitava Roy, Ankur Patel, Rakhee Menon, Archana Sharma, Chakravarthy D. P., Patil D. S. Emission properties of explosive field emission cathodes. Physics of Plasmas, 2011, vol. 18, pp. 103108. DOI: https://doi.org/10.1063/1.3646361
  13. Jun Bing Chuan, Hong Wan, Jie Yang, Fan Zhou. Microstructure Characterization of Graphite Cathodes for Explosive Field-Emission. Applied Mechanics and Materials, 2012, vol. 248, pp. 268‒273. DOI: https://doi.org/10.4028/www.scientific.net/AMM.248.268
  14. Guozhi Liu, Jun Sun, Hao Shao, Changhua Chen, Xiaowei Zhang. Research on an improved explosive emission cathode. J. Phys. D: Appl. Phys., 2009, vol. 42, pp. 125204. DOI: https://doi.org/10.1088/0022-3727/42/12/125204
  15. Suzdal’tsev S. Yu., Shanygin V. Ya., Yafarov R. K. Fieldemission diode with tangential current takeoff from thinfilm nanodiamond/graphite emitter. Technical Physics Letters, 2011, vol. 37, iss. 11, pp. 534–537.
  16. Kaptsov N. A. Elektricheskiye yavleniya v gazakh i vakuume [Electrical phenomena in gases and vacuum]. Moscow, Leningrad, Gos. izd-vo tekhn.-teoret. lit., 1950. 836 p. (in Russian).
  17. Shiffler D., Ruebush M. Emission uniformity and emission area of explosive field emission cathodes. Appl. Phys. Lett., 2001, vol. 79, pp. 2871. DOI: https://doi.org/10.1063/1.1415408
  18. Fan Zhou, Hong Wan, Junbing Chuan, Shuxin Bai, Jie Yang. Explosive electron emission from a surface-modified carbon/ carbon composite cathode. J. Phys. D: Appl. Phys., 2013, vol. 46, pp. 305203. DOI: https://doi.org/10.1088/0022-3727/46/30/305203
  19. Fowler R. H., Nordheim L. W. Electronemission in intense electric fields. Proceedings of the Royal Society of London. Series A, 1928, vol. 119, pp. 173‒181.
  20. Mesyats G. A. Vzryvnaya elektronnaya emissiya [Explosive electron emission]. Moscow, Fizmatlit Publ., 2011. 280 p. (in Russian).
Received: 
17.06.2020
Accepted: 
30.09.2020
Published: 
31.03.2021