of 1
300
400
500
600
700
800
2
3
4
Refractive index, n
Wavelength (nm)
0
1
2
Absorption Coefficient, k
4.0
3.0
2.0
Photon Energy (eV)
Fig. 1S. Optical constants of Cu
2
O substrates measured by
spectroscopic ellipsometry
in the spectra range of interest.
300
400
500
600
700
800
0
1
2
3
Absorbance
Wavelength (nm)
4.0
3.0
2.0
Photon Energy (eV)
50x diluted electrolyte
Fig. 2S. The absorbance spectra for CH
3
CN solution that contained 20 mM LiClO
4
, 0.4
mM Me
10
CoCp
2
+
and 0.04 mM Me
10
CoCp
2
, which was diluted with CH
3
CN by a factor of
50 relative to the solution used in the spectral response measurements.
# Supplementary Material (ESI) for Energy & Environmental Science
# This journal is (c) The Royal Society of Chemistry 2011