Oxygen plasma treatment is commonly used to sterilize gold nanoparticles by removing chemical contaminants from their surface while simultaneously inducing surface activation and functionalization of nanoparticles for biological, electrocatalytic, or electrochemical studies. In this study, we investigate the influence of oxygen plasma treatment on structural and localized surface plasmon resonance (LSPR) spectral changes of anisotropic gold nanorods (AuNRs) immobilized on an indium tin oxide (ITO) glass substrate. Unlike AuNRs deposited on a glass slide, no noticeable structural change or deformation of AuNRs on ITO was observed while increasing the oxygen plasma treatment time. This result indicates that ITO provides structural stability to AuNRs immobilized on its surface. Additionally, single-particle scattering spectra of AuNRs showed the broadening of LSPR linewidth within 60 s of oxygen plasma treatment as a result of the plasmon energy loss contributed from plasmon damping to ITO due to the removal of capping material from the AuNR surface. Nevertheless, an increase in the surface charge on the AuNR surface was observed by narrowing the LSPR linewidth after 180 s of plasma treatment. The electrochemical study of AuNRs immobilized on ITO electrodes revealed the surface activation and functionalization of AuNRs by increasing plasma treatment. Hence, in this study, a significant understanding of oxygen plasma treatment on AuNRs immobilized on ITO surfaces is provided.

The chalcopyrite CuIn (1-x) Ga x Se 2 (CIGS) thin films were grown on Mo substrate by electrochemical atomic layer deposition (E-ALD) of superlattice sequencing 2InSe/2GaSe/1CuSe, recently developed on model Au surface by Stickney and coworkers (J. Electrochem. Soc. 161, D141 (2014)). The cyclic voltammetry studies were conducted on copper, selenium, indium and gallium on molybdenum substrate and CIGS films were grown by different numbers of superlattice sequencing. The deposited films were examined for phase and microstructure formations by X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning tunneling microscopy (STM) and energy dispersive spectroscopy (EDS). The XRD pattern corresponded to those of chalcopyrite crystalline phase of CIGS and the crystallite size increased with the number of cycles or periods of whole superlattice sequencing increased. The SEM and STM results were in line with those of XRD by showing that the particle size increased as the number of E-ALD cycles increased. The EDS results revealed the CIGS with near stoichiometry. Finally, the deposited E-ALD films were shown to be photoelectrochemically active with p-type conductivity. We wish to describe the preparation of CuIn (1-x) Ga x Se 2 (CIGS) by means of electrochemical atomic layer deposition (E-ALD) on Mo substrate of each component element in aqueous solutions at ambient laboratory conditions and to show that the resulting films are photoelectrochemically active with p-type conductivity.Solar energy, the prominent energy source of the universe could be properly utilized for the current increasing trends for energy needs of our entire planet. Alternate energy production technologies like thin film solar cells have been successfully competing traditional energy production methods raised over recent years.1-3 The chalcopyrite Cu(In,Ga)(Se/S) 2 modules of thin films are the promising tool in commercially manufacturing thin film photovoltaic (PV) technologies available in PV market today. 4 The chalcopyrites CIGS are compound semiconductors which are largely known for high absorption coefficient (1 × 10 5 cm −1 ) at photons above the bandgap. 5 The Ga substitution can make the compound with highly adjustable bandgap (1.04 eV for CuInSe 2 (x = 0) to 1.68 eV for CuGaSe 2 (x = 1)) 6 with high stability under high energy irradiation. 7,8 The bandgap of the material is more closely found with the optimum conversion efficiency range (1.4 ∼ 1.5 eV) of solar radiation.9 Because of these properties, it attracted considerable interests by the researchers and industrialists to use CIGS as light-absorbing materials for thin film photovoltaic cells.7-10 Recent works on CIGS have achieved the power conversion efficiency up to 22.6% in laboratory scale. [20][21][22][23] These synthesis methods need larger investment in machinery and workspace which involve highly complicated instruments. The difficulties are with the problems in maintaining the laboratory conditions, complicated procedures and unusual release of heat and toxic byprod...

The strong adsorption of thiol molecules on gold nanorods (AuNRs) results in localized surface plasmon resonance (LSPR) energy loss via chemical interface damping (CID). This study investigated the CID effect induced by thiophenol (TP) adsorption on single AuNRs and the in situ tuning of LSPR properties and chemical interfaces through electrochemical potential manipulation. The potential-dependent LSPR spectrum of bare AuNRs exhibited redshifts and line width broadening owing to the characteristics of capacitive charging, Au oxidation, and oxidation dissolution. However, TP passivation provided stability to the AuNRs from oxidation in an electrochemical environment. Electrochemical potentials induced electron donation and withdrawal, causing changes in the Fermi level of AuNRs at the Au–TP interface, thereby controlling the LSPR spectrum. Additionally, the desorption of TP molecules from the Au surface was electrochemically achieved at the anodic potentials further away from the capacitive charging region, which can be used to tune chemical interfaces and the CID process in single AuNRs.

The chalcopyrite CuIn (1-x) Ga x Se 2 (CIGS) thin films and their cadmium sulfide (CdS) window layer structures (CIGS/CdS) were grown on Mo foil substrate in layer-by-layer fashion by electrochemical atomic layer deposition (E-ALD) and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and photoelectrochemical (PEC) activity. XRD shows distinct pattern changes from chalcopyrite to chalcopyrite plus CdS structures upon adding E-ALD CdS layer to CIGS layers on Mo substrate. SEM shows that uniform and homogeneously distributed nanoparticles of CdS formed on top of CIGS layers, and EDS shows the successful preparation of CIGS/CdS structures with good atomic ratios in each layer. PEC performance reveals that bare CIGS films were of p-type conductivity but that CIGS/CdS structures n-type with p-type response near null.