of 3
Supporting Information
Conductive Polymer (PEDOT) Contacts on p-, n- and n
+
-Si: The Effects of Silicon
Surface Functionalization and PEDOT Conductivity on
the Junction Behavior
Michael G. Walter,
Xueliang Liu, Leslie E. O’Leary,
Bruce S. Brunschwig, and Nathan S. Lewis*
[*] Prof. N. S. Lewis, Corresponding Author
Beckman Institute and Kavli Nanoscience Institute
Division of Chemistry and Chemical Engineering
California Institute of Technology
210 Noyes Laboratory, 127-72
Pasadena, CA 91125 (USA)
E-mail:
nslewis@caltech.edu
S1.
Supplementary Figures
A
B
Figure S1.
(a) Image of a dry PEDOT:PSS conductive polymer co
ntact on an n-Si
electrode. (b) Cross section of drop-cast PEDOT:PSS
films (6.5
±
0.34

m average
thickness).
Figure S2.
Comparison of the
J
-
V
behavior of PEDOT:PSS on a freshly etched n-Si
surface, and an unetched n-Si surface that containe
d a native oxide.
Figure S3.
UV-visible transmittance of thick PEDOT:PSS drop c
ast films and thin spin-
cast films on glass slides.
Calculated Bulk-recombination limited
V
oc
for
PEDOT:PSS / n-Si junctions
n-methyl Si
Device #
H-term Si
Device #
J
sc
V
oc
Calc
recombination
J
sc
V
oc
Calc
recombination
28.74
609
604
56E
17.8
606
592
62B
18.12
590
592
12.1
593
582
8.7
569
573
4.93
561
559
28
600
604
62A
16.9
600
591
62C
17
587
591
11.5
580
581
7
564
568
3.25
542
548
10.82
584
585
56D
calc
8.77
581
574
4.36
560
556
62B 3 days later
5.19
557
559
Table S1:
Calculated bulk-recombination limited open-circuit
voltages (
V
oc
) at various
short-circuit current densities (
J
sc
) of both H-term and CH
3
-terminated n-Si
photoelectrodes using eq. 3
V
oc
=
k
B
T
q
ln
J
sc
L
p
N
D
n
i
2
μ
p
k
B
T
L
p
= 2.0x10
-2
cm,
n
i
= 1.45x10
10
cm
-3
,
N
D
= 1.04x10
16
cm
-3
,

p
= 428 cm
2
V
-1
s
-1
.