Supporting Information:
Laser Modified ZnO/CdSSe Core-Shell Nanowire Arrays for MicroSteganography and Improved Photoconduction
Junpeng Lu1, Hongwei Liu2, Minrui Zheng1, Hongji Zhang1, Sharon Xiaodai Lim1, Eng Soon
Tok1, Chorng Haur Sow1
1
Department of Physics, 2 Science Drive 3, National University of Singapore, 117542, Singapore
2
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology
and Research), 3 Research Link, 117602, Singapore
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Supplementary Section S1: (a) SEM image of ZnO nanowire array. (b) SEM image of
ZnO/CdSSe nanowire arrays. Low-magnification TEM images of ZnO/CdSSe nanowire with (c)
thick shell, and (d) thin shell. Inserts show the SAED patterns of CdSSe and ZnO, respectively.
(e) High-resolution TEM image of (c). Insert shows the SAED pattern of ZnO/CdSSe. (f) Highresolution TEM image of (d). (g) EDX mapping and element line scan of a core/shell nanowire.
Small amount of Zn/Cd element is found existing at the shell/core. This is probably attributed to
the diffusion in the interface between ZnO and CdSSe.
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Supplementary Section S2: PL spectra of pure (a) ZnO nanowires and (b) CdSSe nanowires.
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Supplementary Section S3: Low magnification, SAED pattern and high magnification TEM
images after laser pruning. Each of the particles is crystalline.
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Supplementary Section S4: Measured thermal resistance as a function of distance along the
nanowire.
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Supplementary Section S5: Temperature dependent PL spectra of (a) pristine and (b) laser
pruned nanowire arrays. (c) Low temperature (5 K) PL spectrum of pristine nanowires. The
spectrum was fitted and separated by Lorentz profiles. (d) PL decay traces of pristine region,
laser pruned region and pure CdSSe nanostructures at 300 K. The experimental data was fitted
by y  y0  A1e  x / t1  A2e  x / t2 , the fitting results were listed in the table.
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Supplementary Section S6: (a) FM images, (b) optical microscope images, (c) SEM images and
(d) PL spectra of 6 micropatterns created using different laser powers (3, 5, 16, 18, 25, 33 mW
from i to vi, respectively). (e) Zoom in view PL spectra of v and vi.
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