CC BY
3
i l St. Petersburg Polytechnic University Journal. Physics and Mathematics. 2022 Vol. 15, No. 3.2 Научно-технические ведомости СПбГПУ. Физико-математические науки. 15 (3.2) 2022
Conference materials UDC 681.7.069.24
DOI: https://doi.org/10.18721/JPM.153.205
Ultra-high vacuum formation of silver films for light-emitting tunnel junctions
V. A. Shkoldin , D. V. Levedev , D. V. Permyakov 2, A. E. Petukhov 3,
A. O. Golubok 4, A. V. Arkhipov 5, A. K. Samusev 2, I. S. Mukhin 15
1 St. Petersburg Academic University, St. Petersburg, Russia; 2 ITMO University, St. Petersburg, Russia; 3 St. Petersburg State University, St. Petersburg, Russia; 4 Institute for analytical instrumentation RAS, St. Petersburg, Russia; 5 Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
H shkoldin@spbau.ru
Abstract. Integrated photonics requires compact electrically driven sources of optical radiation for the use in high-performance integrated circuits with optical interconnections in a chip. Light-emitting tunnel junctions represent a promising option of such nanosized light sources, even if their present quantum efficiency is insufficient for practical implementation. We propose a technique for fabrication of such junctions by ultrahigh vacuum forming of thin silver films. Testing showed a high quality and high optical response of the produced films. Such films can serve as substrates for more complicated tunnel junction structures with yet higher quantum efficiency.
Keywords: scanning tunneling microscopy, tunnel contact, emission from a tunnel contact, silver film, photonics, ultrahigh vacuum
Funding: This study was funded by Russian Science Foundation, grant number 21-79-10346.
Citation: Shkoldin V. A., Lebedev D. V., Permyakov D. V., Petukhov A. E., Golubok A. O., Arkhipov A.V., Samusev A. K., Mukhin I. S., Ultra-high vacuum formation of silver films for light-emitting tunnel junctions, St. Petersburg State Polytechnical University Journal. Physics and Mathematics. 15 (3.2) (2022) 31-34. DOI: https://doi.org/10.18721/JPM.153.205
This is an open access article under the CC BY-NC 4.0 license (https://creativecommons. org/licenses/by-nc/4.0/)
Материалы конференции УДК 681.7.069.24
DOI: https://doi.org/10.18721/JPM.153.205
Формирование серебряных плёнок в ультра-высоком вакууме для светоизлучающих туннельных контактов
В. А. Школдин ,2е, Д. В. Лебедев ,34, Д. В. Пермяков 2,
А. О. Голубок 4, А. В. Архипов 5, А. К. Самусев 2, И. С. Мухин 15
1 Академический университет имени Ж.И. Алфёрова РАН, Санкт-Петербург, Россия; 2 Университет ИТМО, Санкт-Петербург, Россия; 3 Санкт-Петербургский государственный университет кино и телевидения, Санкт-Петербург, Россия; 4 Институт аналитического приборостроения РАН, Санкт-Петербург, Россия; 5 Санкт-Петербургский политехнический университет Петра Великого, Санкт-Петербург, Россия
н shkoldin@spbau.ru
Аннотация. Излучающий туннельный контакт является перспективной основой для наноразмерных электрически управляемых источников света, но обладает невысокой квантовой эффективностью для использования в фотонике. Предложен метод создания серебряных плёнок в ультра-высоком вакууме, дающих высокий оптический отклик в туннельном контакте.
© Shkoldin V. A., Lebedev D. V., Permyakov D. V., Petukhov A. E., Golubok A. O., Arkhipov A.V., Samusev A. K., Mukhin I. S., 2022. Published by Peter the Great St.Petersburg Polytechnic University.
Ключевые слова: сканирующая туннельная микроскопия, туннельный контакт, излучение из туннельного контакта, серебряная плёнка, фотоника
Финансирование: Работа выполнена при поддержке Российского Научного Фонда проект № 21-79-10346.
Ссылка при цитировании: Школдин В. А., Лебедев Д. В., Пермяков Д. В., Петухов А. Е., Голубок А. О., Архипов А. В., Самусев А. К., Мухин И. С. Формирование серебряных плёнок в ультра-высоком вакууме для светоизлучающих туннельных контактов // Научно-технические ведомости СПбГПУ. Физико-математические науки. 2022. Т. 15. № 3.2. С. 31-34. DOI: https://doi.org/10.18721/ JPM.153.205
Статья открытого доступа, распространяемая по лицензии CC BY-NC 4.0 (https:// creativecommons.org/licenses/by-nc/4.0/)
Introduction
The progress of computing electronics encounters various limitations, such as heat dissipation efficiency and bandwidth of electrical connections. A prospective approach to conquer these problems consists in inclusion of photonic links and photonic computing components into integrated circuits. Present photonics technologies offer many of the necessary components, though the size difference between the modern CMOS electronic components and optical sources represents a bottleneck on the way to their integration [1].
Tunnel junctions provide a promising basis for construction of compact optical sources. The visible and near infrared light emission effect supported by inelastic electron tunneling has been known for about 50 years [2]. The size of the resulting light source is defined by the size of electrical contacts. However, at present the quantum efficiency of such sources remains insufficient for their practical implementation: its typical value is as low as 106 photons per electron, and further efforts are necessary to increase this figure.
Here we report on our investigation of a method to fabricate clean Ag layers in ultrahigh vacuum (UHV) conditions, which represents an initial step to produce a light-emitting tunnel junctions.
Experiment
Sample fabrication and characterization were performed in ultrahigh vacuum conditions at the pressure not worse than 5 109 mbar. All processes were conducted in a research modular platform Nanolab, which incorporates a scanning tunneling microscope (STM) Omicron VT AFM XA 50/500 (Scienta Omicron, Germany), equipment for thin film deposition, a low-energy
electron diffractometer (LEED) and some other tools. The sample was fabricated on a highest quality vacuum cleaved mica (Ted Pella, USA) serving as a substrate.
The mica plate was installed on a custom-made STM sample holder equipped with an optical lens. The plate was fixed by four screws; preliminary electric contact at its edges was secured with two-component silver-filled epoxy (EPO-TEK H21D). Then the top layer of mica was scratched and covered by a copper tape with an attached copper ring. After transferring the sample into the vacuum chamber, pumping and annealing, the copper tape was removed by pulling the ring with the chamber manipulator. The resulting cleaving exposed a clean mica surface. Then, a 30 nm layer of silver was deposited on the freshly cleaved mica by thermal evaporation. The silver film quality was estimated with the Low Energy Fig. 1. Low energy electron diffraction Electrons Diffraction (LEED) technique: the bright peaks pattern from Ag film in the LEED image (Fig. 1) demonstrate its crystallinity.
© Школдин В. А., Лебедев Д. В., Пермяков Д. В., Петухов А. Е., Голубок А. О., Архипов А. В., Самусев А. К., Мухин И. С., 2022. Издатель: Санкт-Петербургский политехнический университет Петра Великого.
4
Condensed matter physics
nm Then the sample was examined by the STM. Surface topography images showed formation of large grains (Fig. 2). Studies of light emission induced by STM current were performed using the optical system described in detail in [3]: the emitted light was directed to a single photon counter ID 120 (IDQuantique, Sweden) which work in visible and near infrared regions (400-900 nm). Quantum efficiency of the source based on the tunnel junction between the Ag film surface and a Pt/Ir STM tip was estimated to be about 2 -10"6 photon per electron at -2.5 V bias voltage. This estimate was calculated in the same way as the one in [4]. Notably, the current-voltage characteristics measured during the experiment showed distinct features around ±2.5 V, presumably associated with light emission from the tunnel junction assisted by optical levels [5].
Fig 2. STM image of Ag film
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■ — +t ■ + + *+t M —
u c OJ
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Voltage (V)
Fig. 3. Estimated quantum efficiency of tunnel junction between the silver film and Pt/Ir STM tip
Conclusion
The tested silver film has a relatively high quantum efficiency, about 2106 photon/el., as compared to the one of the previously studied gold films, which had efficiencies of about 9107 photon/el.. This developed technique and material can be used for producing more complicated tunnel junctions coupled to nanoantennas.
Acknowledgments
This work was supported by the Russian Science Foundation (project no. 21-79-10346 of the Russian Science Foundation). The studies were carried out using the equipment of the St. Petersburg State University Research Park "Centre for Physical methods of surface investigation".
REFERENCES
1. Parzefall M., Novotny L., Optical antennas driven by quantum tunneling: a key issues review. Reports on Progress in Physics. 11(82) (2019) 112401.
2. Lambe J., McCarthy S. L., Light Emission from Inelastic Electron Tunneling . Phys. Rev. Lett. 14(37) (1976) 923-925.
3. Lebedev D. V., Mozharov A. M., Bolshakov A. D., Shkoldin V. A., Permyakov D. V., Golubok A. O., Samusev A. K., Mukhin I. S., Indirect Detection of the Light Emission in the Local Tunnel Junction . physica status solidi (RRL) — Rapid Research Letters. 3(14) (2020) 1900607.
4. Lebedev D. V., Shkoldin V. A., Mozharov A. M., Larin A. O., Permyakov D. V., Samusev A. K., Petukhov A. E., Golubok A. O., Arkhipov A. V., Mukhin I. S., Nanoscale Electrically Driven Light Source Based on Hybrid Semiconductor / Metal Nanoantenna. The Journal of Physical Chemistry Letters. 20(13) (2022) 4612—4620.
5. Lebedev D. V., Shkoldin V. A., Mozharov A. M., Golubok A. O., Permyakov D. V., Samusev A. K., Mukhin I. S., Indirect observation of the light emission in the tunnel junction with metal nanodisk. AIP Conference Proceedings. 2300 (2020) 020080.
THE AUTHORS
SHKOLDIN Vitaliy A.
shkoldin@spbau.ru ORCID: 0000-0002-1014-5401
GOLUBOK Alexander O.
aogolubok@mail.ru ORCID: 0000-0001-9970-9172
LEBEDEV Denis V.
denis.v.lebedev@gmail.com ORCID: 0000-0001-5389-2899
PERMYAKOV Dmitry V.
d.permyakov@metalab.ifmo.ru ORCID: 0000-0003-2708-9140
PETUKHOV Anatoliy E.
anatoliy.petukhov@spbu.ru ORCID: 0000-0001-9362-3589
ARKHIPOV Alexander V.
arkhipov@rphf.spbstu.ru
SAMUSEV Anton K. a.samusev@metalab.ifmo.ru ORCID: 0000-0002-3547-6573
MUKHIN Ivan S.
imukhin@yandex.ru
ORCID: 0000-0001-9792-045X
Received 12.08.2022. Approved after reviewing 14.09.2022. Accepted 14.09.2022.
© Peter the Great St. Petersburg Polytechnic University, 2022
