Abstract
We have made a comparative study of the performance of spin polarized photocathodes based on molecular beam epitaxy (MBE) grown GaAs with Be-doping and on liquid phase epitaxy (LPE) grown GaAs with Zn-doping. The experiments were performed on GaAs (100), (110), and (111) surfaces atT-300 K. The photoelectron spin polarization (P) of the MBE-photocathodes is face dependent reaching 49% for the (111) surface, a value close to P=50% predicted by theory. In contrast for the LPE-photocathodes P is significantly lower (19≲P≲36%). Possible causes for the higher polarization of the MBE-photocathodes are investigated. The influence of the Zn- and Be-dopant is elucidated by theoretical model calculations which shows that replacing the Zn-dopant by Be reduces significantly the depolarization at very low temperatures, but not at room temperature. It is therefore concluded that theinterface region between the GaAs substrate and the MBE-GaAs layer grown on top of it strongly influences the performance of the source.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Eminyan, M., Lampel, G.: Phys. Rev. Lett.45, 1171 (1980)
Wang, G.-C., Dunlap, D.I., Celotta, R.J., Pierce, D.T.: Phys. Rev. Lett.42, 1349 (1979);43, 90 (1979)
Sinclair, C.K.: in: High energy physics with polarized beams on polarized targets. Proc. of the 1980 Intl. Symposium, EXS38, p. 27. Lausanne: Birkhäuser 1981
Pierce, D.T., Meier, F.: Phys. Rev. B13, 5484 (1976)
Alvarado, S., Hopster, H., Feder, R., Pleyer, H.: Solid State Comm. (1981)
Alvarado, S.F., Ciccacci, F., Campagna, M.: Appl. Phys. Lett. (in print)
Vermaak, J.S., Snyman, L.W., Auret, F.D.: Surface contamination, Vol. 2, p. 595. 1979
Reihl, B., Erbudak, M., Campbell, D.M.: Phys. Rev. B19, 6358 (1979)
Pierce, D.T., Celotta, R.J., Wang, G.-C., Unertl, W.N., Galejs, A., Kuyatt, C.E., Mielczarek, S.R.: Rev. Sci. Instrum.51, 478 (1980)
D'yakonov, M.I., Perel', V.I.: Sov. Phys. JETP33, 1053 (1971)
D'yakonov, M.I., Perel', V.I.: Sov. Phys. Semicond.7, 1551 (1974)
Reihl, B., Erbudak, M.: Appl. Phys. Lett.33(7), 584 (1978)
Burt, M.G., Inkson, J.C.: J. Phys. D10, 721 (1977)
James, L.W., Antypas, G.A., Edgecumbe, J., Moon, R.L., Bell, R.L.: J. Appl. Phys.42, 4976 (1971)
Fishman, G., Lampel, G.: Phys. Rev. B16, 820 (1977) and ref. therein
Lampel, G., Eminyan, M.: J. Phys. Soc. Japan49, 627 (1980)
Pierce, D.T., Wang, G.-C., Celotta, R.J.: Appl. Phys. Lett.35(3), 720 (1979)
We note that P is smallest for the (110) surface for both LPE- and MBE-sources, indicating that mechanism (a) (and possibly (b)) might be operative in reducing P in both cases
Safarov, V.I., Titkov, A.N.: J. Phys. Soc. Japan49, 623 (1980)
Meyer, J.R., Bartoli, F.J.: Phys. Rev. B23, 5413 (1981), and refs. therein
Green, A.E.S., Sellin, D.L., Zachor, A.S.: Phys. Rev.184, 1 (1969)
Bir, G.L., Aronov, A.G., Pikus, G.E.: Sov. Phys. JETP42, 705 (1976)
The MBE layer was kindly provided by K. Ploog of the Max-Planck Institut für Festkörperforschung, Stuttgart, FRG
Author information
Authors and Affiliations
Additional information
On leave from the Istituto di Fisica Universitá di Modena I-41100 Modena Italy.
Rights and permissions
About this article
Cite this article
Alvarado, S.F., Ciccacci, F., Valeri, S. et al. Spin polarized photoemission from molecular beam epitaxy-grown be-doped GaAs. Z. Physik B - Condensed Matter 44, 259–264 (1981). https://doi.org/10.1007/BF01294161
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01294161