Abstract
The possibility of lowering the work function Φ in several materials by adsorption of alkali metals has been extensively used in the pioneer works on photoemission, making it possible to perform experiments with conventional light sources. This procedure has proved to be very effective in semiconductors, leading to the development of Negative Electron Affinity (NEA) photocathodes 1. Under such conditions, the bottom of the bulk conduction band lies above the potential barrier at the surface, so that electrons excited to the conduction band can escape into vacuum. In practice NEA condition is achieved in heavily p-doped semiconductors (to encourage downward band bending at the surface) by adding in Ultra High Vacuum (UHV) environment a thin film (one to some atomic layers) of cesium rich oxide on the clean semiconductor surface. The activation procedure, developed for technological purposes, is well known, at least for gallium arsenide, and NEA GaAs photocathodes are widely used in photomultiplier tubes.
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References
W.E. Spicer, Apol. Phys. 12 115 (1977), and references therein.
G. Lampel, in Proceeding of the 12th International Conference on the Physics of Semiconductors, Stuttgart 1974, ed. by M.H. Pilkuhn ( Teubner, Stuttgart 1974 ) p. 743.
D.T. Pierce, R.J. Celotta, G.C. Wang, W.N. Unertl, A. Galejs, C.E. Kuyatt, and S.R. Mielczarek, Rev. Sci. Instrum. 51, 478 (1980).
H.J. Drouhin, C. Hermann, and G. Lampel, Phys, Rev. B 31, 3859 (1985).
H.J. Drouhin, C. Hermann, and G. Lampel, Phys. Rev. B 31, 3872 (1985).
S.F. Alvarado, F. Ciccacci, S. Valeri, M. Campagna, R. Feder, and H. Pleyer, Z. Phys.B 44, 259 (1981).
F. Ciccacci, S.F. Alvarado, and S. Valeri, J. Apnl. Phys. 53, 4395 (1982).
F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, and G. Lampel, Appl. Phys, Lett.5A, 632 (1989).
R.C. Miller, D.A. Kleinmann, and A.C. Gossard, in Proceedings of the 16th International Conference on the Physics of Semiconductors, Edingburgh 1978, ed. by B.L.H. Wilson ( Institute of Physics, London 1979 ) p. 1043.
S.F. Alvarado, F. Ciccacci, and M. Campagna, Appl. Phys. Lett. 39, 615 (1981).
R. Houdré, C. Hermann, G. Lampel, P.M. Frijlink, and A.C. Gossard, Phys. Rev, Lett 55, 734 (1985).
F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, and G. Lampel, Vuoto XVI, 185 (1986).
R. Houdré, C. Hermann, G. Lampel, and A.C. Gossard, Physica Scripta T 13, 241 (1986).
F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, G. Lampel, and F. Alexandre, in Excitons in Confined Systems, Springer Proceedings in Physics 25, ed. by R. Del Sole, A. D’Andrea, and A. Lapiccirella ( Springer-Verlag, Berlin 1988 ) p. 185.
F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, G. Lampel, and F. Alexandre, Solid State Electron. 31, 489 (1988).
For the band parameters of the A1GaAs alloy, see S. Adachi, J. Appl. Phys. 58, R1 (1985).
H.J. Drouhin, and M.Eminyan, Rev. Sci. Instrum. 57, 1052 (1986).
F. Meier and B.P. Zakharchenya (ed.’s), Optical Orientation, Series Modern Problems in Solid State Sciences, Vol. 8 ( Elsevier, Amsterdam 1984 ).
M.I. D’yakonov and V.I. Perel’, Sov. Phys, JEPT 33 1053 (1971) Zh. Eksp. Teor. Fiz. LQ, 1954 (1971)].
G. Fishman and G. Lampel, Phys. Rev. B 16, 820 (1977).
D.T. Pierce, F. Meier, and P. Zuercher, Appl. Phys. Lett. 26, 670 (1975).
J. Kessler, Polarized Electrons, Springer Series on Atoms and Plasma 1 ( Springer Verlag, Berlin 1985 ).
R. Feder (ed.), Polarized Electrons in Surface Physics, Advances Series in Surface Science (World Scientific, Singapore 1985 ).
C. Sinclair, in High Energy Physics with Polarized Beams and Polarized Targets, ed. by C. Joseph and J. Soffer ( Birkhauser Verlag, Lausanne 1981 ) p. 27.
P. Zorabedian, SLAC Report 248 (Standford University, 1982 ).
S.F. Alvarado, F. Ciccacci, H. Riechen, and M. Campagna, unpublished.
N.E. Christensen, E. Molinari, and G. Bachelet, Solid State Commun.56, 125 (1985).
F. Ciccacci, E. Molinari, and N.E. Christensen, Solid State Commun. 62, 1 (1987).
D. Conrath, T. Heindroeff, A. Hermanni, N. Ludwig, and E. Reichert, Appt. Phys. 20, 1955 (1979).
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Ciccacci, F. (1989). Photoemission from AlGaAs/GaAs Heterojunctions and Quantum Wells under Negative Electron Affinity Conditions. In: Fasol, G., Fasolino, A., Lugli, P. (eds) Spectroscopy of Semiconductor Microstructures. NATO ASI Series, vol 206. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-6565-6_20
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