Post-deposition air-annealing effects of based thin films and heterojunction solar cell devices are studied by photoelectron spectroscopy and admittance spectroscopy. Ultraviolet photoelectron spectroscopy reveals type inversion at the surface of the as-prepared films, which is eliminated after exposure of several minutes to air due to the passivation of surface Se deficiencies. X-ray photoelectron spectroscopy demonstrates that air annealing at 200 C leads to a decreased Cu concentration at the film surface. Admittance spectroscopy of complete heterojunction solar cells shows that the surface type inversion is restored by the chemical bath used for CdS deposition. Air annealing of the finished devices at 200 C reduces the type inversion again due to defect passivation. Our results also show that oxygenation leads to a charge redistribution and to a significant compensation of the effective acceptor density in the bulk of the absorber. This is consistent with the release of Cu from the absorber surface and its redistribution in the bulk.
REFERENCES
1.
2.
R. A.
Mickelsen
, W. S.
Chen
, H. R.
Hsiao
, and V.
Lowe
, IEEE Trans. Electron Devices
ED-31
, 542
(1984
).3.
K. Mitchell, C. Eberspacher, J. Ermer, and D. Pier, Proceedings of the 20th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1988), p. 1384.
4.
R. J.
Matson
, R.
Noufi
, R. K.
Ahrenkiel
, R. C.
Powell
, and D.
Cahen
, Sol. Cells
16
, 495
(1986
).5.
6.
R. W.
Birkmire
, L. C.
DiNetta
, P. G.
Lasswell
, J. D.
Meakin
, and J. E.
Phillips
, Sol. Cells
16
, 419
(1986
).7.
R. R. Potter, C. Eberspacher, and L. B. Fabick, Proceedings of the 18th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1985), p. 1659.
8.
J. R.
Tuttle
, J. S.
Ward
, T. A.
Berens
, M. A.
Contreras
, K. R.
Ramanathan
, A. L.
Tennant
, J.
Keane
, E. D.
Cole
, K.
Emery
, and R.
Noufi
, Mater. Res. Soc. Symp. Proc.
426
, 143
(1996
);J. Hedström, H. Olsen, M. Bodegard, A. Kylner, L. Stolt, D. Hariskos, M. Ruckh, and H. W. Schock, Proceedings of the 23rd IEEE Photovoltaic Specialists Conference (IEEE, New York, 1993), p . 364.
9.
10.
M. Schmitt, U. Rau, and J. Parisi, Proceedings of the 13th European Photovoltaic Solar Energy Conference (Stephens, Bedford, 1995), p. 1969.
11.
T.
Walter
, R.
Herberholz
, C.
Müller
, and H. W.
Schock
, J. Appl. Phys.
80
, 4411
(1996
).12.
R.
Herberholz
, M.
Igalson
, and H. W.
Schock
, J. Appl. Phys.
83
, 318
(1998
).13.
14.
15.
P. H.
Mauk
, H.
Tavakolian
, and J. R.
Sites
, IEEE Trans. Electron Devices
ED-37
, 422
(1990
).16.
D.
Schmid
, M.
Ruckh
, F.
Grunwald
, and H. W.
Schock
, J. Appl. Phys.
73
, 2902
(1993
);D.
Schmidt
, M.
Ruckh
, H. W.
Schock
, Sol. Energy Mater. Sol. Cells
41/42
, 281
(1995
).17.
R. Herberholz, H. W. Schock, U. Rau, J. H. Werner, T. Haalboom, T. Gödecke, F. Ernst, C. Beilharz, K.W. Benz, and D. Cahen, Proceedings of the 26th IEEE Photovoltaic Specialists Conference (IEEE, Piscataway, 1998), p. 323.
18.
R. Herberholz, U. Rau, H. W. Schock, T. Haalboom, T. Gödecke, F. Ernst, C. Beilharz, K. W. Benz, and D. Cahen, Eur. Phys.: J. AP 6 (in press).
19.
M.
Topic
, F.
Smole
, and J.
Furlan
, Sol. Energy Mater. Sol. Cells
49
, 311
(1997
).20.
A.
Niemeegers
, M.
Burgelman
, R.
Herberholz
, U.
Rau
, D.
Hariskos
, and H. W
Schock
, Prog. Photovoltaics
6
, 407
(1998
).21.
22.
M. A.
Green
, F. D.
King
, and J.
Shewchun
, Solid-State Electron.
17
, 551
(1974
).23.
The charge neutrality level is defined as the energy distance between the Fermi level and the valence band edge which would lead to a neutral surface or interface; see, e.g., E. H. Rhoderick and R. H. Williams, Metal-Semiconductor Contacts, 2nd ed. (Clarendon, Oxford, 1988), p. 15.
24.
T. Kamins, Polycrystalline Silicon for Integrated Circuit Applications (Kluwer, Boston, 1998), p. 171.
25.
U. Rau, D. Braunger, and H. W. Schock, in Polycrystalline Semiconductors V - Bulk Materials, Thin Films, and Devices, edited by J. H. Werner, H. P. Strunk, H. W. Schock, “Solid State Phenomena” (Scitech, Uettikon am See, Switzerland, 1999), p. 409.
26.
L. Stolt, M. Bodegard, J. Hedström, J. Kessler, M. Ruckh, K. O. Velthaus, and H. W. Schock, Proceedings of the 11th European Photovoltaic Solar Energy Conference (Stephens, Bedford, UK, 1992), p. 120.
27.
D.
Schmid
, M.
Ruckh
, and H. W.
Schock
, Appl. Surf. Sci.
103
, 409
(1996
).28.
H. Lüth, Surfaces and Interfaces of Solids, 2nd ed. (Springer-Verlag, Berlin, 1993).
29.
L. L.
Kazmerski
, O.
Jamjoum
, J. F.
Wagner
, P. J.
Ireland
, and K. J.
Bachmann
, J. Vac. Sci. Technol. A
1
, 668
(1983
);L. L.
Kazmerski
, P. J.
Ireland
, O.
Jamjoum
, S. K.
Deb
, R. A.
Mickelsen
, and W.
Chen
, J. Vac. Sci. Technol.
19
, 467
(1981
).30.
G. A.
Medvedkin
, M. Y.
Yakushev
, A. E.
Hill
, R. D.
Pilkington
, and R. D.
Tomlinson
, Cryst. Res. Technol.
31
, 209
(1996
).31.
32.
33.
M. Köntges, Diploma thesis, University of Oldenburg, 1998 (unpublished).
34.
35.
L.
Stolt
, J.
Hedström
, J.
Kessler
, M.
Ruckh
, K. O.
Velthaus
, and H. W.
Schock
, Appl. Phys. Lett.
62
, 597
(1993
).36.
K. Ramanathan, H. Wiesner, S. Asher, D. Niles, R. N. Bhattacharya, J. Keane, M. A. Contreras, and R. Noufi, Proceedings of the 2nd World Conference on Photovoltaic Energy Conversion, edited by J. Schmid, H. A. Ossenbrink, P. Helm, H. Ehmann, and E. D. Dunlop (E. C. Joint Res. Centre, Luxembourg, 1998), p. 477.
37.
T. Wada, S. Hayashi, Y. Hashimoto, S. Nishiwaki, T. Sato, and M. Nishitina, in Proceedings of the 2nd World Conference on Photovoltaic Energy Conversion, edited by J. Schmid, H. A. Ossenbrink, P. Helm, H. Ehmann, and E. D. Dunlop (E. C. Joint Res. Centre, Luxembourg, 1998), p. 403.
38.
L.
Kronik
, B.
Mishori
, E.
Fefer
, Y.
Shapira
, and W.
Riedl
, Sol. Energy Mater. Sol. Cells
51
, 21
(1998
).39.
M. Ruckh, D. Schmid, M. Kaiser, R. Schäffler, T. Walter, H. W. Schock, Proceedings of the 1st World Conference on Photovoltaic Energy Conversion (IEEE, New York, 1994), p. 156.
40.
V. Probst, J. Rimmasch, W. Riedl, W. Stetter, J. Holz, H. Harms, F. Karg, and H. W. Schock, Proceedings of the 1st World Conference on Photovoltaic Energy Conversion (IEEE, New York, 1994), p. 144.
41.
U.
Rau
, M.
Schmitt
, F.
Engelhardt
, O.
Seifert
, J.
Parisi
, W.
Riedl
, J.
Rimmasch
, and F.
Karg
, Solid State Commun.
107
, 59
(1998
).42.
D.
Cahen
, P. J.
Ireland
, L. L.
Kazmerski
, and F. A.
Thiel
, J. Appl. Phys.
57
, 4761
(1985
).43.
See, e.g., J. McMurry, Organic Chemistry, 2nd ed. (Brooks&Cole, Belmont, 1988), p. 41.
44.
K.
Gartsman
, L.
Chernyak
, V.
Lyakhvitskaya
, D.
Cahen
, V.
Didik
, V.
Koslovsky
, R.
Malkovich
, E.
Skoryatina
, and V.
Usacheva
, J. Appl. Phys.
82
, 4282
(1997
);45.
S. B.
Zhang
, S.-H.
Wei
, and A.
Zunger
, Phys. Rev. Lett.
78
, 4059
(1997
).46.
A.
Klein
, C.
Pettenkofer
, and W.
Jaegermann
, J. Appl. Phys.
80
, 5039
(1996
).47.
D. W.
Niles
, M.
Al-Jassim
, and K.
Ramanathan
, J. Vac. Sci. Technol. A
17
, 291
(1999
).
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