Me. Rincon et al., PHOTOELECTROCHEMICAL BEHAVIOR OF CHEMICALLY DEPOSITED CDSE AND COUPLED CDS CDSE SEMICONDUCTOR-FILMS/, Solar energy materials and solar cells, 52(3-4), 1998, pp. 399-411
Photoelectrochemical effects at chemically deposited CdSe thin films (
2000 Angstrom) coupled with as-prepared and air annealed (250 degrees
C) CdS films have been investigated by monitoring open-circuit voltage
(V-oc) and short-circuit current density (I-sc) at varying incident l
ight intensities and for different heat-treatments temperatures. Two c
onsecutive chemical baths were used in the coupled system. Each bath h
as been optimized in earlier studies for the deposition of highly phot
osensitive CdS and CdSe thin films. The photoelectrochemical behavior
of single and coupled films was investigated in ferricyanide redox cou
ples. The enhanced short-circuit photocurrent of the as-deposited CdS/
CdSe system, despite their lower photosensitivity, indicated that char
ge separation improved in the coupled system. The role of post-deposit
ion thermal treatments in improving the photoelectrochemical cell char
acteristics and stability of coupled semiconductors was investigated.
Excellent I-V properties were obtained for CdSe and CdS250/CdSe photoe
lectrodes annealed at 280 degrees C. For the coupled system: V-oc = 96
0 mV; I-sc = 8.6 mA/cm(2); fill factor (ff) = 0.53 and cell efficiency
(eta) = 4.2%. The linearity of V-oc/ln(I-L) and I-sc/I-L plots suppor
ts the Schottky-Mott model for these interfaces. The stability of the
coupled photoanode is superior to that of the CdSe only-film for the i
nitial 3 h. (C) 1998 Elsevier Science B.V. All rights reserved.