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The effect of a bilayer of different dimension silver nanoparticles (Ag NPs) on light trapping in silicon solar cells is investigated. Here, we report on the improved performance of silicon solar cells by integrating two layers of silver nanoparticles of different sizes. We experimentally examine the plasmonic near-field and far-field effects of bilayer Ag NPs embedded within an anti-reflective DLC layer on the optical and electrical characteristics of silicon solar cells. The two-dimensional differences in the size of Ag NPs were driven by Field-Emission Scanning Electron Microscopy. The surface plasmon resonance of the two-dimensional nanoparticles was estimated from the absorption optical spectra. External quantum efficiency measurements showed that near-field or far-field plasmonic effects altered with the Ag NPs size. The effect of far fields was confirmed by measuring the solar cell performance under AM 1.5 G illumination. The effect of the far-field in the cell containing two layers of Ag NPs, which outer layer is larger dimensions NPs, improves the current density up to 38.4 mA/cm2 (by 70% compared to the bare reference cell).

Delafossite CuFeO2 (CFO) has attracted much attention as a candidate p-type photocathode for photoelectrochemical (PEC) solar hydrogen production. In this paper first, a detailed electrochemical study was carried out in order to determine the best potential range for the potentiostatic deposition of nanostructured CFO on FTO glass. The structural and morphological properties of prepared samples were characterized by XRD and FESEM. Optical and photoelectrochemical investigations show that the sample prepared at − 0.7 V exhibits the best optical properties, charge separation, and charge transfer among prepared samples. We also provided direct evidence of surface states as charge trapping centers cause carrier recombination and limit photovoltage and charge transfer at SCLJ (semiconductor/liquid junction). Deposition of plasmonic Au nanoparticles (NPs) embedded in the diamond-like carbon (DLC) scaffold on the surface of CuFeO2 not only improved optical properties but also passivated these surface states and enhanced the PEC performance, consequently.

The aim of the present study is to explore the 3-D micromorphology of human canine teeth materials using multifractal analysis through atomic force microscopy (AFM). The 3-D surfaces of ten extracted canine teeth of a group of 40 year old men were studied (enamel, inter enamel, inter dentin, and cementum) by AFM images in tapping mode and on square areas of 1 μm × 1 μm (512 × 512 points). The AFM images and surface multifractal analysis confirm the dependency of surface micromorphology to their structure–property of these materials across the length scales of the teeth structural architecture. Surface statistical parameters and hence, multifractal approach have been considered as reliable and sensitive tools for quantifying the 3-D surface microtexture changes of human canine teeth materials. The surface of inter dentin had the most irregular topography (the width spectrum Δα = 2.8361, value bigger than all the other Δα sample values), while the most regular topography (the width spectrum Δα = 2.6804, value lower than all the other sample values) was found in cementum. It has been concluded that multifractal analyses can be used as mathematical tools to explore the 3-D micromorphology of human canine teeth materials.

Iron nanoparticles in amorphous hydrogenated carbon films (FeNPs@a-C:H) were prepared with RF-sputtering and RFPECVD methods by acetylene gas and Fe target. In this paper, deposition and sputtering process were carried out under influence of different initial pressure gas. The morphology and roughness of surface of samples were studied by AFM technique and also TEM images show the exact size of FeNPs and encapsulated FeNPs@a-C:H. The localized surface plasmon resonance peak (LSPR) of FeNPs was studied using UV–vis absorption spectrum. The results show that the intensity and position of LSPR peak are increased by increasing initial pressure. Also, direct energy gap of samples obtained by Tauc law is decreased with respect to increasing initial pressure.

Carbon nanotubes (CNTs) decorated with Cu2O particles were grown on a Ni catalyst layer deposited on a Cu substrate by thermal chemical vapor deposition from liquid petroleum gas. Ni catalyst nanoparticles with different sizes were produced in an electroplating system at 45 °C using the corrosive effect of H2SO4 which was added to solution. These nanoparticles provide the nucleation sites for CNT growth avoiding the need for a buffer layer. The surface morphology of the Ni catalyst films and CNT growth over this catalyst was studied by scanning electron microscopy (SEM). High temperature surface segregation of the Cu substrate into the Ni catalyst layer and its exposition to O2 at atmospheric environment, during the CNTs growth, lead to the production of CNTs decorated with about 6 nm Cu2O nanoparticles. We used SEM to study the surface characteristics of Ni catalyst films and characteristic of grown CNTs. Raman spectroscopy, transmission electron microscopy (TEM), electron diffraction (EDX), X-ray diffraction, and X-ray photoelectron spectroscopy (XPS) revealed the formation of CNTs. The selected area electron diffraction pattern, EDX, and XPS studies show that these CNTs were decorated with Cu2O nanoparticles. This way of fabrication is the easiest and lowest cost method.

1. Existent mistakes in AFM Images Analysis section (lines 3 and 5) are only typos and should be correct to Rrms and \h[. 2. In page 3 (line 5), DL = N/L is correct. Please see [2] and [3]. 3. In the Eq. 5, Df 1⁄4 8 c 2 . Please see [2, 4, 5]. 4. Since 2D and 3D AFM images in [6] present the better angle of view, I suggest the authors of comment pay more attention to them. I think, they describe the process of fabrication of particles clearly. It is clear that, some typos cannot depreciate the value of paper.