Ionization energy and electron affinity of clean and oxidized Al xGa1-xN(0001) surfaces

H. Nienhaus; M. Schneider; S. P. Grabowski; W. Mönch; R. Dimitrov; O. Ambacher; M. Stutzmann

doi:10.1557/proc-680-e4.5

Ionization energy and electron affinity of clean and oxidized Al _xGa_1-xN(0001) surfaces

H. Nienhaus, M. Schneider, S. P. Grabowski, W. Mönch, R. Dimitrov, O. Ambacher, M. Stutzmann

TUM Emeriti of Excellence

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

13 Scopus citations

Abstract

Ionization energies and electron affinities of clean Al_xGa _1-xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N⁺-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 10⁸ Langmuirs and the ionization energy increases by approximately 2 eV.

Original language	English
Title of host publication	Wide-Bandgap Electronics
Publisher	Materials Research Society
Pages	96-101
Number of pages	6
ISBN (Print)	1558996168, 9781558996168
DOIs	https://doi.org/10.1557/proc-680-e4.5
State	Published - 2001
Event	2001 MRS Spring Meeting - San Francisco, CA, United States Duration: 16 Apr 2001 → 20 Apr 2001

Publication series

Name	Materials Research Society Symposium Proceedings
Volume	680
ISSN (Print)	0272-9172

Conference

Conference	2001 MRS Spring Meeting
Country/Territory	United States
City	San Francisco, CA
Period	16/04/01 → 20/04/01

Access to Document

10.1557/proc-680-e4.5

Cite this

@inproceedings{c6568ff937ea4342bd02c8176a30a81b,

title = "Ionization energy and electron affinity of clean and oxidized Al xGa1-xN(0001) surfaces",

abstract = "Ionization energies and electron affinities of clean AlxGa 1-xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N+-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 108 Langmuirs and the ionization energy increases by approximately 2 eV.",

author = "H. Nienhaus and M. Schneider and Grabowski, {S. P.} and W. M{\"o}nch and R. Dimitrov and O. Ambacher and M. Stutzmann",

year = "2001",

doi = "10.1557/proc-680-e4.5",

language = "English",

isbn = "1558996168",

series = "Materials Research Society Symposium Proceedings",

publisher = "Materials Research Society",

pages = "96--101",

booktitle = "Wide-Bandgap Electronics",

note = "2001 MRS Spring Meeting ; Conference date: 16-04-2001 Through 20-04-2001",

}

Nienhaus, H, Schneider, M, Grabowski, SP, Mönch, W, Dimitrov, R, Ambacher, O & Stutzmann, M 2001, Ionization energy and electron affinity of clean and oxidized Al _xGa_1-xN(0001) surfaces. in Wide-Bandgap Electronics. Materials Research Society Symposium Proceedings, vol. 680, Materials Research Society, pp. 96-101, 2001 MRS Spring Meeting, San Francisco, CA, United States, 16/04/01. https://doi.org/10.1557/proc-680-e4.5

Ionization energy and electron affinity of clean and oxidized Al _xGa_1-xN(0001) surfaces. / Nienhaus, H.; Schneider, M.; Grabowski, S. P. et al.
Wide-Bandgap Electronics. Materials Research Society, 2001. p. 96-101 (Materials Research Society Symposium Proceedings; Vol. 680).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

TY - GEN

T1 - Ionization energy and electron affinity of clean and oxidized Al xGa1-xN(0001) surfaces

AU - Nienhaus, H.

AU - Schneider, M.

AU - Grabowski, S. P.

AU - Mönch, W.

AU - Dimitrov, R.

AU - Ambacher, O.

AU - Stutzmann, M.

PY - 2001

Y1 - 2001

N2 - Ionization energies and electron affinities of clean AlxGa 1-xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N+-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 108 Langmuirs and the ionization energy increases by approximately 2 eV.

AB - Ionization energies and electron affinities of clean AlxGa 1-xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N+-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 108 Langmuirs and the ionization energy increases by approximately 2 eV.

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