The linear and nonlinear optical response of native‐oxide covered rippled Si templates with nanoscale periodicity

Abstract

Fabrication of dense arrays of nanowires by growth on nanostructured substrates appears to be a promising approach for producing functional nanoscale devices. Ion beam irradiation under carefully controlled conditions produces selforganized ripple patterns on silicon substrates, on which Ag nanowire arrays with nanoscale periodicity have been grown successfully. Here, the linear and nonlinear optical response from native-oxide-covered Si(001) templates, with ripple periodicity between $20 and $50 nm, is reported. Reflection anisotropy spectroscopy (RAS) shows a small, broad peak at $2.5 eV of $1 Â 10 À3 amplitude. The RAS response decreases as the periodicity of the ripple structure increases. The nonlinear second-harmonic (SH) response from the samples was also measured, using unamplified femtosecond excitation at 800 nm, by rotating the linear polarized input and detecting either the sor p-polarized SH output. A decrease in response with increased ripple structure periodicity was observed for the p-in/p-out configuration, when the plane of incidence was orthogonal to the average ripple orientation. Possible origins of the response and future experiments are discussed. For the substrates themselves, self-organized fabrication of nanoscale templates has been explored, for example by the controlled annealing of vicinal alumina [6,7]. Low-energy ion beam irradiation is another established method for fabricating self-organized, nanoscale periodic patterns on flat solid substrates [8], which attracted interest as a method to create templates for functional nanostructures [9]. Nanodot arrays and nanoripples with short range order and adjustable periodicity have been fabricated on various

Self-organized nanopatterning of silicon surfaces by ion beam sputtering

“…It should be noted that for many of them it is not relevant whether they are produced with or without metal co-deposition or if the nanostructures are crystalline or amorphous. As shown, the pattern anisotropy can be exploited as growth template but also interesting optical properties may appear from the nanopatterned silicon itself [289]. Regarding future applications in micro(opto)electronic devices, the formation of confined crystalline silicon nanoripples has also been realized on SiO 2 [290].…”

Optical characterisation of plasmonic nanostructures on planar substrates using second–harmonic generation

“…Figure 6 shows polar plots of the α-p and α-s response of the rippled nanostructures with arrays of Ag NPs of varying aspect ratio (Table 1), and Table 5 and 6 show the parameter values extracted from the fits. A detailed study of the SHG response from the native-oxide-covered rippled Si(001) substrate at this excitation wavelength has been published previously [37]. The rippled Si(001) response is comparable in size to that of native-oxide-covered Si(001), while Fig.…”

An analytic approach to modeling the optical response of anisotropic nanoparticle arrays at surfaces and interfaces

“…The experimental procedures used for the growth and characterization of the three distinct plasmonic systems have been reported in detail previously [18,27,28]. In the first system, anisotropic Pb nanostructures were grown on clean Si(5 5 7) surfaces by self-assembly under ultra-high vacuum (UHV) conditions [27].…”