Optical properties of silicon nanowire arrays formed by metal-assisted chemical etching: evidences for light localization effectстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 19 июля 2013 г.
Аннотация:We study the structure and optical properties of arrays of silicon nanowires (SiNWs) with a
mean diameter of approximately 100 nm and length of about 1–25 μm formed on crystalline
silicon (c-Si) substrates by using metal-assisted chemical etching in hydrofluoric acid
solutions. In the middle infrared spectral region, the reflectance and transmittance of the formed SiNW arrays can be described in the framework of an effective medium with the
effective refractive index of about 1.3 (porosity, approximately 75%), while a strong light
scattering for wavelength of 0.3 † 1 μm results in a decrease of the total reflectance of 1%-
5%, which cannot be described in the effective medium approximation. The Raman scattering
intensity under excitation at approximately 1 μm increases strongly in the sample with
SiNWs in comparison with that in c-Si substrate. This effect is related to an increase of the
light-matter interaction time due to the strong scattering of the excitation light in SiNW array.
The prepared SiNWs are discussed as a kind of „black silicon‟, which can be formed in a
large scale and can be used for photonic applications as well as in molecular sensing.