Porosification-reduced optical trapping of silicon nanostructures.
Metal-assisted chemical etching (MACE) was carried out to fabricate solid silicon nanowires (s-SiNWs) and mesoporous silicon nanowires (mp-SiNWs). Total reflection and transmission were measured using an integrated sphere to study optical properties of the MACE-generated silicon nanostructures. Without NW aggregation, mp-SiNWs vertically standing on a mesoporous silicon layer trap less light than s-SiNWs over a wavelength range of 400-800 nm, owing to porosification-enhanced optical scattering from the rough inner surfaces of the mesoporous silicon skeletons. Porosification substantially weakens the NW mechanical strength; hence the elongated mp-SiNWs aggregate after 30 min etching and deteriorate optical trapping.
Department of Physics, Institute of Advanced Materials (IAM), Hong Kong Baptist University (HKBU), 224 Waterloo Road, Kowloon Tong, Hong Kong SAR, People's Republic of China.
Wai-Keung
WK
To
Junxue
J
Fu
Xiongbo
X
Yang
V A L
VA
Roy
Zhifeng
Z
Huang
D008670:Metals / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D013053:Spectrophotometry
D008670:Metals; D011108:Polymers; D012825:Silicon