Therefore, the overall detected gold content reduces. Figure 4 EDX test showing the Au-Si percentage within different laser cycling. (A) 2 cycles. (B) 3 cycles. (C) 4 cycles. (D) 5 cycles. Figure 5 Gold nanoparticle variation with number of cycles and dwell time. 1 ms (red), 0.75 ms (green), and 0.50 ms (purple). Light reflectance The nanofibrous structure can significantly influence optical properties, which can differ considerably with those of the bulk materials. This type of structure enhances

optical absorption due to surface plasmon excitation in the metal nanoparticle [10]. The micro-nanoscale surface roughness of the treated substrate could also increase light absorption Anlotinib manufacturer due to the multiple reflections Selleckchem DihydrotestosteroneDHT in micro-cavities and the variation of light incident angles. Metal surfaces with roughness on the scale of the optical wavelength are found to have a strong coupling of the incident light and become discolored as a result of selective surface plasmon absorption.In order to investigate the samples’ enhanced absorption behavior in the visible region, a spectroradiometer

was employed with a broad wavelength range of 250 to 1,200 nm. The measured integrating reflectance spectra are illustrated in Figure 6, where the red curve represents the reflectance of the unirradiated gold-silicon sample showing a high reflective intensity around 4,000 a.u. Figure 6 Measured integrating reflectance spectra. (A) 0.25 ms, (B) 0.50 ms, and (C) 1.00 ms. The dark red curve represents the untreated sample, while

the olive green, purple, light blue, and orange curves represent the reflection spectrum of the fibrous nanostructure layer with 2, 3, 4, and 5 cycles over visible wavelength, respectively, at different dwell times. The fibrous nanostructure increases the surface area by more than an order of magnitude which causes the radiation to pass through a longer distance before being reflected back. Therefore, a photon incident on a structured surface is likely to undergo more than one reflection before leaving the surface. Comparing the reflection spectrum to that of pure silicon nanofibers obtained from a previous experiment repeated on silicon wafer [20], we can conclude that the fibrous structure is the main attribute for light enhancement. GNA12 The embedded gold particles will further enhance such multi-reflection, by increasing the intensity of reflection. This is evident from Figure 6A. At 2 scanning cycles and 0.25 ms of dwell time, the quantity of nanofiber is the lowest, but the percentage content of gold reaches the highest. Therefore, the learn more enhancement effect is the most noticeable. It was observed that the reflectance decreased as the scanning cycle increased. As the scanning cycle increased, more fibrous nanostructures were generated and the thickness of the deposition increased, hence more effective in reflecting illumination.