Type transformation in CuInSe2 and CuInS2 solar cells is an important issue with far reaching consequences. In the present study, the presence of a p-n homojunction inside CuInS2 in a TiO2CuInS2 device is revealed with a detailed impedance spectroscopy and capacitance study. A n-type CuInS2 film with a thickness of 40nm is found at the TiO2 (n-type)/CuInS2 (p-type) interface. The effective donor density of this n-type film is 2×1017cm3 at 400K and is higher than the effective acceptor density in the remaining p-type CuInS2, being 4×1016cm3 at 400K. Both densities decrease upon increasing the temperature. This is explained by the activation of a CuIn acceptor state in n-type CuInS2 and a thermally activated hole trap in p-type CuInS2.

1.
J. A. M.
AbuShama
,
S.
Johnston
,
T.
Moriarty
,
G.
Teeter
,
K.
Ramanathan
, and
R.
Noufi
,
Prog. Photovoltaics
12
,
39
(
2004
).
2.
T.
Glatzel
,
D. F.
Marron
,
T.
Schedel-Niedrig
,
S.
Sadewasser
, and
M. C.
Lux-Steiner
,
Appl. Phys. Lett.
81
,
2017
(
2002
).
3.
R.
Scheer
,
R.
Klenk
,
J.
Klaer
, and
I.
Luck
,
Sol. Energy
77
,
777
(
2004
).
4.
K.
Ramanathan
 et al,
Prog. Photovoltaics
11
,
225
(
2003
).
5.
M. I.
Alonso
,
K.
Wakita
,
J.
Pascual
,
M.
Garriga
, and
N.
Yamamoto
,
Phys. Rev. B
63
,
075203
(
2001
).
6.
R.
Klenk
,
J.
Klaer
,
R.
Scheer
,
M. C.
Lux-Steiner
,
I.
Luck
,
N.
Meyer
, and
U.
Ruhle
,
Thin Solid Films
480
,
509
(
2005
).
7.
M. A.
Green
,
K.
Emery
,
D. L.
King
,
Y.
Hishikawa
, and
W.
Warta
,
Prog. Photovoltaics
15
,
35
(
2007
).
8.
M.
Gratzel
,
Nature (London)
414
,
338
(
2001
).
9.
M.
Nanu
,
J.
Schoonman
, and
A.
Goossens
,
Adv. Mater. (Weinheim, Ger.)
16
,
453
(
2004
).
10.
B.
van der Zanden
,
C.
Joanta
,
H.
Donker
,
M.
Nanu
, and
B.
Meester
,
Proceedings of the 21st European Photovoltaic Solar Energy Conference
,
Dresden, Germany
,
267
(
2007
).
11.
R.
Herberholz
 et al,
Eur. Phys. J.: Appl. Phys.
6
,
131
(
1999
).
12.
L.
Chernyak
,
K.
Gartsman
,
D.
Cahen
, and
O. M.
Stafsudd
,
J. Phys. Chem. Solids
56
,
1165
(
1995
).
13.
L. L.
Kerr
,
S. S.
Li
,
S. W.
Johnston
,
T. J.
Anderson
,
O. D.
Crisalle
,
W. K.
Kim
,
J.
Abushama
, and
R. N.
Noufi
,
Solid-State Electron.
48
,
1579
(
2004
).
14.
M.
Nanu
,
L.
Reijnen
,
B.
Meester
,
J.
Schoonman
, and
A.
Goossens
,
Chem. Vap. Deposition
10
,
45
(
2004
).
15.
M.
Nanu
,
L.
Reijnen
,
B.
Meester
,
A.
Goossens
, and
J.
Schoonman
,
Thin Solid Films
431
,
492
(
2003
).
16.
B.
Tell
,
J. L.
Shay
, and
H. M.
Kasper
,
J. Appl. Phys.
43
,
2469
(
1972
).
17.
J.
Parkes
,
R. D.
Tomlinso
, and
M. J.
Hampshir
,
J. Cryst. Growth
20
,
315
(
1973
).
18.
J.
Parkes
,
R. D.
Tomlinso
, and
M. J.
Hampshir
,
Solid-State Electron.
16
,
773
(
1973
).
19.
R. D.
Tomlinson
,
E.
Elliott
,
J.
Parkes
, and
M. J.
Hampshire
,
Appl. Phys. Lett.
26
,
383
(
1975
).
20.
P.
Migliora
,
B.
Tell
,
J. L.
Shay
, and
H. M.
Kasper
,
Appl. Phys. Lett.
24
,
227
(
1974
).
21.
P. W.
Yu
,
Y. S.
Park
,
S. P.
Faile
, and
J. E.
Ehret
,
Appl. Phys. Lett.
26
,
717
(
1975
).
22.
B.
Tell
,
S.
Wagner
, and
P. M.
Bridenbaugh
,
Appl. Phys. Lett.
28
,
454
(
1976
).
23.
S.
Wagner
,
J. L.
Shay
,
P.
Migliora
, and
H. M.
Kasper
,
Appl. Phys. Lett.
25
,
434
(
1974
).
24.
P. W.
Yu
,
S. P.
Faile
, and
Y. S.
Park
,
Appl. Phys. Lett.
26
,
384
(
1975
).
25.
B.
Tell
and
P. M.
Bridenbaugh
,
J. Appl. Phys.
48
,
2477
(
1977
).
26.
R. K.
Ahrenkiel
,
L. L.
Kazmerski
,
R. J.
Matson
,
C.
Osterwald
,
T. P.
Massopust
,
R. A.
Mickelsen
, and
W. S.
Chen
,
Appl. Phys. Lett.
43
,
658
(
1983
).
27.
L. L.
Kazmerski
,
O.
Jamjoum
,
P. J.
Ireland
,
R. A.
Mickelsen
, and
W. S.
Chen
,
J. Vac. Sci. Technol.
21
,
486
(
1982
).
28.
L. L.
Kazmerski
,
Thin Solid Films
57
,
99
(
1979
).
29.
R.
Matson
,
R.
Noufi
,
R. K.
Ahrenkiel
,
R. C.
Powell
, and
D.
Cahen
,
Sol. Cells
16
,
495
(
1986
).
30.
R.
Matson
,
R.
Noufi
,
K. J.
Bachmann
, and
D.
Cahen
,
Appl. Phys. Lett.
50
,
158
(
1987
).
31.
D.
Schmid
,
M.
Ruckh
, and
H. W.
Schock
,
Appl. Surf. Sci.
103
,
409
(
1996
).
32.
D.
Schmid
,
M.
Ruckh
,
F.
Grunwald
, and
H. W.
Schock
,
J. Appl. Phys.
73
,
2902
(
1993
).
33.
I. M.
Kotschau
and
H. W.
Schock
,
J. Phys. Chem. Solids
64
,
1559
(
2003
).
34.
Y.
Yan
,
K. M.
Jones
,
J.
Abushama
,
M.
Young
,
S.
Asher
,
M. M.
Al Jassim
, and
R.
Noufi
,
Appl. Phys. Lett.
81
,
1008
(
2002
).
35.
D.
Cahen
,
J. M.
Gilet
,
C.
Schmitz
,
L.
Chernyak
,
K.
Gartsman
, and
A.
Jakubowicz
,
Science
258
,
271
(
1992
).
36.
S.
Richter
,
Y.
Manassen
, and
D.
Cahen
,
Phys. Rev. B
59
,
10877
(
1999
).
37.
M.
Krunks
,
V.
Mikli
,
O.
Bijakina
, and
E.
Mellikov
,
Appl. Surf. Sci.
142
,
356
(
1999
).
38.
L.
Kavan
and
M.
Gratzel
,
Electrochim. Acta
40
,
643
(
1995
).
39.
See EPAPS Document No. E-JAPIAU-102-120714 for a table with all transition voltages and slopes of the C2-ϕ measurements and the mathematical analysis of the capacitance of the four situations shown in Fig. 6. This document can be reached through a direct link in the online article's HTML reference section or via the EPAPS homepage (http://www.aip.org/pubservs/epaps.html).
40.
M.
Kleinfeld
and
H. D.
Wiemhofer
,
Solid State Ionics
28
,
1111
(
1988
).
41.
M.
Kleinfeld
and
H. D.
Wiemhofer
,
Ber. Bunsenges. Phys. Chem.
90
,
711
(
1986
).
42.
J. J. M.
Binsma
,
L. J.
Giling
, and
J.
Bloem
,
J. Lumin.
27
,
35
(
1982
).
43.
M.
Nanu
,
F.
Boulch
,
J.
Schoonman
, and
A.
Goossens
,
Appl. Phys. Lett.
87
(
2005
).
44.
R.
Herberholz
,
M.
Igalson
, and
H. W.
Schock
,
J. Appl. Phys.
83
,
318
(
1998
).
45.
M.
Igalson
and
H. W.
Schock
,
J. Appl. Phys.
80
,
5765
(
1996
).
46.
T.
Walter
,
R.
Herberholz
, and
H. W.
Schock
,
Solid State Phenom.
(Polycrystalline Semiconductors IV),
51–52
,
309
(
1996
).

Supplementary Material

You do not currently have access to this content.