Self-decorated Au nanoparticles on antireflective Si pyramids with improved hydrophobicity
- SUNAG Laboratory, Institute of Physics, Bhubaneswar 751 005, Odisha (India)
- Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, Kolkata 700 064 (India)
Post-deposition annealing mediated evolution of self-decorated Au nanoparticles (NPs) on chemically etched Si pyramids is presented. A distinct transformation of Si surfaces from hydrophilic to hydrophobic is initially found after chemical texturing, showing an increase in contact angle (CA) from 58° to 98° (±1°). Further improvement of hydrophobicity with CA up to ∼118° has been established after annealing a 10 nm thick Au-coated Si pyramids at 400 °C that led to the formation of Au NPs on Si facets along with self-ordering at the pyramid edges. Detailed x-ray diffraction studies suggest the evolution of crystalline Au NPs on strained Si facets. Microstructural studies, however, indicate no mixing of Au and Si atoms at the Au/Si interfaces, instead of forming Au nanocrystals at 400 °C. The improved hydrophobicity of Si pyramids, even with Au NPs can be explained in the light of a decrease in solid fractional surface area according to Wenzel's model. Moreover, a sharp drop in specular reflectance from Si pyramids in the range of 300–800 nm, especially in the ultraviolet region up to ∼0.4% is recorded in the presence of Au NPs by ultraviolet-visible spectroscopy, reflecting the possible use in photovoltaic devices with improved antireflection property.
- OSTI ID:
- 22594559
- Journal Information:
- Journal of Applied Physics, Vol. 119, Issue 13; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ATOMS
DEPOSITION
GOLD
INTERFACES
MICROSTRUCTURE
MIXING
NANOPARTICLES
NANOSTRUCTURES
PHOTOVOLTAIC EFFECT
SILICON
SPECTROSCOPY
SURFACE AREA
SURFACES
ULTRAVIOLET RADIATION
X-RAY DIFFRACTION