S
1
Supp
orting
Information for:
P
LASTIC
M
ORPHOLOGICAL
R
ESPONSE TO
S
PECTRAL
S
HIFTS
D
URING
I
NORGANIC
P
HOTOTROPIC
G
ROWTH
K
ATHRYN
R.
H
AMANN
†
,
M
ADELINE
C.
M
EIER
†
,
N
ATHAN
S.
L
EWIS
†,‡
,
*
,
A
ZHAR
I.
C
ARIM
†,‡
,
*
†
Division of Chemistry and Chemical
Engineering
California Institute of Technology
Pasadena, CA 91125
‡
Beckman Institute
California Institute of Technology
Pasadena, CA 91125
*Corresponding Authors:
nslewis@caltech.edu
,
aic@caltech.edu
S
2
Figure S1.
Representative top
-
view SEMs of films generated using the indicated
λ
avg
illumination for
t
= 2.00 min
with a characteristic feature pitch marked using a double arrow.
Figure S2.
2D FTs generated from top
-
view SEM data of films generated using the indicated λ
avg
for
t =
2.00 min
.
Figure S
3
.
(a)
-
(d)
R
epresentative
top
-
view
and (e)
-
(h) cross
-
sectional SEMs of
film
s generated using λ
avg
= 955 nm
for the indicated
t
.
S
3
Figure S
4
.
(a)
R
epresentative
top
-
view
and (b) cross
-
sectional SEMs of
film
s generated using λ
0
= 727 nm for
t
0
=
2.00 min and then extended using λ
1
= 955 nm for
t
1
= 3.50 min.
Figure S
5
.
(a)
Representative
top
-
view
and (b) cross
-
sectional SEMs of
films
generated using λ
0
= 955 nm for
t
0
=
2.00 min and then extended using λ
1
= 528 nm for
t
1
= 3.00 min.
S
4
Figure S
6
.
Flowchart with representative cross
-
sectional SEM
s
detailing the morphological evolution of
films
generated initially using
λ
0
= 528
nm for
t
0
= 2.00 min
and then extended in a second deposition step using either
λ
1
=
727 nm
or 955 nm for the indicated additional time.
S
5
Figure S
7
.
Flowchart with representative cross
-
sectional SEM
s
detailing the morphological evolution of
films
generated initially usin
g
λ
0
= 955 nm for
t
0
= 2.00 min
and then extended in a second deposition step using either
λ
1
=
727 nm
or 528 nm for the indicated additional time.
Figure S
8
.
Simulated spatial profiles representing the
normalized
time
-
averaged E
-
field magnitude
, |E|
,
resulting from
= 955 nm illumination of simplified structures representative of the indicated experimentally observed structures,
but with the height of a single feature adjusted to model initial extension using
1
.
Red represents maximal magnitude
and blue minimal.
S
6
Figure S
9
.
Schematic of an electrode assembly with an attached Au
-
topped Si section.
Figure S
10
.
Schematic
depicting inorganic phototropic growth using sequential, discrete spectral inputs. For
t < t
0
(
t
0
= 2.00 min), the deposition substrate is illuminated using light from a LED source with an intensity
-
weighted average
emission
wavelength of λ
0
.
Then, at
t
0
, the LED emitting at λ
0
is turned off, the illumination is replaced with light from
a LED source e
mitting at λ
1
, and
inorganic phototropic
growth is continued
with this condition
for
t
>
t
0
.
S
7
Figure S1
1
.
Representative
X
-
ray diffract
ogram
of a
Se
-
Te film
with reflections characteristic of Se
-
Te and the Au
substrate indicated.
1
,
2
Figure S1
1
presents a representative X
-
ray diffractogram of a
Se
-
Te
film
. The reflections
in this diffractogram are consistent with a
substitutional alloy of Se and Te in a trigonal crystal
structure common to each element in the pure phase and indicate a polycrystalline film.
1
,
2
Figure S
1
2
.
Representative energy
-
dispersive X
-
ray spectrum
of a Se
-
Te
film
.
S
8
Figure S
1
3
.
Complex refractive index of
characteristic of a
Se
-
Te
film
.
The wavelength
-
dependent complex index of refraction values characteristic of Se
-
Te were
derived from experimentally acquired spectroscopic ellipsometry data. A J. A. Woollam VASE
ellipsometer was used to obtain amplitude ratio and phase difference (Ψ and
Δ) data from
electrodeposited Se
-
Te material, and the WVASE software package (J. A. Woollam) was utilized
to calculate from this data the complex index of refraction which is presented in Figure S13.
λ
avg
/ nm
n
k
528
3.00
1.68
727
3
.59
1.18
955
3.77
0.62
Table S
1
.
Point values of the real and imaginary parts of the complex refractive index characteristic of deposited Se
-
Te at the
λ
avg
values utilized in this work.
Average Wavelength
Weighted by Intensity
/ nm
Average Wavelength
Weighted by Photon Count
/ nm
528
529
727
727
955
956
Table S2.
Average emission wavelengths of the LED sources
used
in this work as weighted by intensity (
λ
avg
) and by
photon count.
S
9
REFERENCES
(1) Smith, T. W.; Smith, S. D.; Badesha, S. S. Chemical Alloying, a Novel Method for the
Preparation of Homogenous Se
x
Te
1
-
x
Alloys.
J. Am. Chem. Soc.
1984
,
106
, 7247
-
7248.
(2) Mayers, B.; Gates, B.; Yin, Y.; Xia, Y. Large
-
Scale Synthesis of Monodisperse
Nanorods of
Se/Te Alloys Through a Homogenous Nucleation and Solution Growth Process.
Adv. Mater.
2001
,
13
, 1380
-
1384.