Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces
The exploitation of the photoelectric effect is a prominent method for the in situ measurement of the absolute work function of a surface. In the case of metallic surfaces, the Fowler theory is routinely applied for fitting or extrapolating the measured photoelectric yield data to determine the work...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2022-03-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0078380 |
| _version_ | 1811260325073256448 |
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| author | A. Heiler R. Friedl U. Fantz |
| author_facet | A. Heiler R. Friedl U. Fantz |
| author_sort | A. Heiler |
| collection | DOAJ |
| description | The exploitation of the photoelectric effect is a prominent method for the in situ measurement of the absolute work function of a surface. In the case of metallic surfaces, the Fowler theory is routinely applied for fitting or extrapolating the measured photoelectric yield data to determine the work function value. However, for the reliable application of the Fowler method, attention must be paid to the experimental sensitivity to the photoelectric behavior close to the threshold, which is mainly determined by the signal-to-noise ratio for photocurrent detection and the available photon energies used for irradiation. This is illustrated by means of applying a photoelectric work function measurement system during a Cs coating process of a metal surface, where insufficiently low photon energies or an unfavorable noise level can lead to a severe overestimation of the work function of the order of 1 eV. By a sufficient enhancement of the photoelectric sensitivity, it is now unveiled that ultra-low surface work functions of 1.25 ± 0.10 eV can be generated via caesiation of metallic surfaces (here molybdenum and stainless steel) under vacuum conditions of 10−6–10−5 mbar, which is most probably the result of the formation of an oxidized Cs adlayer. |
| first_indexed | 2024-04-12T18:45:46Z |
| format | Article |
| id | doaj.art-ec017fd4ae09480582be59ad58e76b22 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-12T18:45:46Z |
| publishDate | 2022-03-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-ec017fd4ae09480582be59ad58e76b222022-12-22T03:20:37ZengAIP Publishing LLCAIP Advances2158-32262022-03-01123035339035339-1110.1063/5.0078380Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfacesA. Heiler0R. Friedl1U. Fantz2Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, GermanyAG Experimentelle Plasmaphysik, Universität Augsburg, D-86135 Augsburg, GermanyMax-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, GermanyThe exploitation of the photoelectric effect is a prominent method for the in situ measurement of the absolute work function of a surface. In the case of metallic surfaces, the Fowler theory is routinely applied for fitting or extrapolating the measured photoelectric yield data to determine the work function value. However, for the reliable application of the Fowler method, attention must be paid to the experimental sensitivity to the photoelectric behavior close to the threshold, which is mainly determined by the signal-to-noise ratio for photocurrent detection and the available photon energies used for irradiation. This is illustrated by means of applying a photoelectric work function measurement system during a Cs coating process of a metal surface, where insufficiently low photon energies or an unfavorable noise level can lead to a severe overestimation of the work function of the order of 1 eV. By a sufficient enhancement of the photoelectric sensitivity, it is now unveiled that ultra-low surface work functions of 1.25 ± 0.10 eV can be generated via caesiation of metallic surfaces (here molybdenum and stainless steel) under vacuum conditions of 10−6–10−5 mbar, which is most probably the result of the formation of an oxidized Cs adlayer.http://dx.doi.org/10.1063/5.0078380 |
| spellingShingle | A. Heiler R. Friedl U. Fantz Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces AIP Advances |
| title | Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces |
| title_full | Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces |
| title_fullStr | Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces |
| title_full_unstemmed | Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces |
| title_short | Impact of the photoelectric threshold sensitivity on the work function determination—Revealing ultra-low work functions of caesiated surfaces |
| title_sort | impact of the photoelectric threshold sensitivity on the work function determination revealing ultra low work functions of caesiated surfaces |
| url | http://dx.doi.org/10.1063/5.0078380 |
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