The direct synthesis of nanostructured electrode materials on three‐dimensional substrates is important for their practical application in electrochemical cells without requiring the use of organic additives or binders. In this study, we present a simple two‐step process to synthesize a stable core–shell structured cobalt sulfide/cobalt aluminum hydroxide nanosheet (LDH‐S) for pseudocapacitor electrode application. The cobalt aluminum layered double hydroxide (CoAl‐LDH) nanoplates were synthesized in basic aqueous solution with a kinetically‐controlled thickness. Owing to the facile diffusion of electrolytes through the nanoplates, thin CoAl‐LDH nanoplates have higher specific capacitance values than thick nanoplates. The as‐grown CoAl‐LDH nanoplates were transformed into core–shell structured LDH‐S nanosheets by a surface modification process in Na2S aqueous solution. The chemically robust cobalt sulfide (CoS) shell increased the electrochemical stability compared to the sulfide‐free CoAl‐LDH electrodes. The LDH‐S electrodes exhibited high electrochemical performance in terms of specific capacitance and rate capability with a galvanostatic discharge of 1503 F g−1 at a current density of 2 A g−1 and a specific capacitance of 91 % at 50 A g−1.
Reduction of biselenites into polyselenides in interlayer space of layered double hydroxides
Solid State Sciences 80 (2018) 110 - 115
A selenous acid (H2SeO3) precursor was intercalated as biselenite (HSeO3−) ions into the interlayer gallery of carbonated magnesium aluminum layered double hydroxide (MgAl-LDH) in aqueous solution. Reduction reaction of selenous ions by aqueous hydrazine solution produced polyselenide intercalated LDHs which were consecutively exchanged with iodide through redox reaction under iodine vapor. The polyselenide containing LDHs adsorbed iodine vapor spontaneously and triiodide was incorporated in the interlayer space followed by formation of selenium polycrystalline phase. Two dimensional framework of MgAl-LDH is strong enough to resist against the reducing power of hydrazine as well as oxidation condition of iodine. The SEM data demonstrated that the shapes of LDH polycrystalline have little changed after the above redox reactions. The polyselenide and iodide LDH products were analyzed by XRD, Infrared and Raman spectra which strongly suggested the horizontal arrangement of polyselenide and triiodide in gallery space of LDHs.
Transparent AgI−CuI heterojunctions with high rectifying diode behavior were prepared via vapor-phase iodization of metal thin films on transparent conducting oxide substrates. At room temperature, Ag and Cu metal thin films were quickly transformed into the transparent and wellcrystallized β-phase of AgI and the γ-phase of CuI, respectively. The AgI and CuI films exhibited n-type and p-type semiconductor properties, respectively, with wide band gaps. The heterojunctions were obtained by applying the CuI film to the AgI film in a sequential iodization process. AgI compounds generally have poor air-stability under light, making them suboptimal for use in electronic applications. Here, we used a CuI top layer to inhibit the photodecomposition of the AgI bottom layer, resulting in an air-stable and smooth AgI−CuI film. We also propose a simple patterning method for the AgI−CuI layer using selective decomposition of AgI without the need for lithography equipment or toxic chemicals. Although there is metal ion exchange between the two layers, each layer has a different chemical composition and crystal structure; therefore, the AgI−CuI heterojunction exhibits pn-diode behavior with a rectifying ratio of 9.4 × 104 , which is comparable to that of other transparent pn-diodes. These findings open a new path for electronic application of AgI materials.
Complexing agent-assisted highly dense CuInSe2 thin films prepared by one-step electrochemical deposition
Journal of Electroanalytical Chemistry 808 (2018) 211–217
Highly dense CuInSe2 (CISe) thin films were electrochemically deposited on Mo-coated soda-lime glass substrates in aqueous solution. Three compounds, CuCl2, InCl3, and SeO2, were used as precursors with glycine or oxalic acid as complexing agents. The deposition process was carefully selected through preliminary study of the individual electrochemical properties of the three precursors. To achieve ideal stoichiometry and uniform deposition of CISe thin films, the reaction temperature and acidity of precursor solution were investigated. As the reaction temperature increased, Cu deficiency was observed in the CISe thin film. The density and surface morphology of CISe films prepared by one-step electrodeposition were affected strongly by the acidity of deposition solution. The addition of HCl to solution improved the density and surface roughness of as-deposited CISe films. Denser and larger grain size CISe polycrystalline films were prepared in oxalic acid solution. Two-step heat treatments for the prepared CISe samples were applied to fabrication of CISe photovoltaic devices without an additional Se source.
Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals
J. Phys. Chem. Lett. 2017, 8, 565−570
High-quality and millimeter-sized perovskite single crystals of CsPbBr3 and Cs4PbBr6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs4PbBr6 crystals, which have a 0D perovskite structure, exhibited more than one order of magnitude higher PL intensity than CsPbBr3, which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr6]4−octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.
Bioinspired polydopamine-layered double hydroxide nanocomposites: controlled synthesis and multifunctional performance
RSC Adv.,2016,6, 24952
A biomimetic multifunctional nanocomposite was synthesized, in which a polydopamine (PDA) thinfilm was
deposited on a layered double hydroxide (LDH) through an interlayer polymerization. Kinetic controlled
polymerization of dopamine (DA) in a basic buffer solution under a nitrogen atmosphere provided
a synthetic pathway for the nanostructured PDA/LDH composites without polymer agglomerates,
allowing the crystallinity of the pristine LDH nanoparticles to be maintained. The contraction of the
interlayer spacing for the (00l)reflection of PDA/LDH nanocomposites demonstrated intercalation of
PDA into the LDH interlayer space. The catalytic activity of the PDA/LDH nanocomposites was evaluated
by observing the reduction ofp-nitrophenol in the presence of NaBH4, in which the PDA layer acts as
a protection layer against surface contamination of the nanocomposites. Electrochemical capacitive
performance was also observed due to the strong adhesion of PDA to the Ni foam electrode. The
nanostructure of the PDA/LDH nanocomposites induced by interlayer polymerization drove the
incorporative organic–inorganic functional materials with blocked surfaces and improved the
electrochemical properties, providing a reliable synthetic pathway to prepare multifunctional nanohybrid
Synthesis of oleic acid-capped CuInS2nanocrystals from bimetallic hydroxide precursor
Thin Solid Films 603 (2016) 243–248
CuInS2 colloidal nanocrystals were synthesized via a facile solution-processed method, using a CuIn(OH)5
precursor. The Cu–In metal hydroxide precursor was prepared by co-precipitation in aqueous solution: an aqueous NaOH solution was reacted with a metal cation solution containing Cu2+ and In 3+ ions at room temperature. Oleic acid was added as a surfactant and bis(trimethyldisilyl)sulfide was injected to provide a sulfur source for the formation of CuInS2 nanocrystals. The CuInS2 colloidal nanocrystals had mixed crystal structures of zincblende and wurtzite, confirmed by XRD and TEM. The CuInS2 nanoparticles were of average size 5.6 nm and had a 1:1:2 chemical composition. Paste of the as-prepared CuInS2 nanocrystals were coated as a thinfilm absorber layer for photovoltaic cells by doctor blading, yielding cell efficiency of 1.26%.
Nanostructured Cobalt Hydroxide Thin Films as High Performance Pseudocapacitor Electrodes by Graphene Oxide Wrapping
Dalton Trans. 2015, 44, 16119
We synthesized binder-free Co(OH)2nanocrystals on nickel electrodes by the ammonia transfer method in an aqueous solution and kinetically-controlled their thickness and height to enhance the capacitance through the facile diffusion of electrolytes in the nanocrystals. As thinner Co(OH)2films were developed, the specific capacitance increased up to 1260 F g^−1 at a current density of 10 A g^−1. A thin layer of graphene oxide (GO) was used to wrap the Co(OH)2 nanocrystals to create a pseudocapacitor with high specific capacitance and good cyclic stability. This synthetic strategy enabled us to maximize the electrochemical cell performance, reaching a specific capacitance of 2710 F g^−1 under 10 A g^−1. The GO coating provides an effective method to increase adhesion on the nickel electrodes and to reduce the decomposition of Co(OH)2during the charge–discharge process under high pH conditions. The prepared GO/Co
(OH)2 nanocomposite layers provided not only high electron mobility but also ionic conductivity, especially when operated at a high current density
Synthesis and Nanostructures of Metal Selenide Precursors for Cu(In,Ga)Se2 Thin-Film Solar Cells
ChemSusChem 2015, 8, 2407–2413
Ananoink solution-based process was developed as alowcosting methodfor the fabrication of Cu(In,Ga)Se
2 (CIGSe)thinfilm photovoltaic cells. The sonochemical synthesis of CIGSe nanocrystalsof thenanoink throughstep-by-step mixing of the reactants was investigated. To achieve the ideal stoichiometry of Cu(In0.7Ga0.3)Se2 to tune the bandgap and to fabricate high-efficiency photovoltaic cells, the synthetic parameters, the concentration of hydrazine, and the amount used of the gallium precursor were investigated. As the hydrazine concentration increased, gallium loss was observed in the CIGSe product.
The gallium content in the reactantmixture strongly affected the metal stoichiometry of the prepared CIGSe nanocrystals. The nanoink solution based fabrication of thin-film photovoltaic cells was also explored, andthe resulting device showed aconversion efficiency of 5.17 %.
Fluorescein dye intercalated layered double hydroxides for chemically stabilized photoluminescent indicators on inorganic surfaces
Dalton Trans., 2014, 43, 8543
A new photoactive thinfilm of layered double hydroxide (LDH) nanocrystals containing fluorescein dyes
(LDH-F) has been developed by self-assembly of the LDH nanocrystals and well-controlled intercalation
of the dyes in organic media. XRD results and absorption spectra confirmed the highly oriented interlayer
arrangement of the dianionic form of thefluorescein dyes in the LDH interlayers, in which the dye molecules were electrostatically immobilized between the positively charged LDH layers with a monolayer
packing structure. An intensity weighted average PL lifetime was estimated to be 1.45 ns andfluorescence
lifetime imaging microscopy revealed that the individual LDH nanocrystals on the LDH-F film had largely
similar lifetimes, which were ascribed to the uniform loading offluorescein dyes onto the LDH matrix
Enhanced Catalytic Activity of Platinum Nanoparticles by Exfoliated Metal Hydroxide Nanosheets
ChemCatChem 2014, 6, 113–118
A novel 2-dimensional catalytic system was developed in which platinum nanoparticles (Pt NPs) were immobilized on exfoliated MgAl-layered double hydroxide (LDH) nanosheets through an electrostatic self-assembly between negatively charged Pt NPs and positively charged LDH nanosheets. The LDH nanosheets effectively provided the large double sides of hydroxide functionality to absorb the Pt NPs, as well as fast diffusion rates of the incoming reactants into catalyst surfaces. This new nanostructure improved the rate of reaction, turnover frequency and reaction durability of Pt NPs on LDH nanosheet without significant loss in conversion efficiencies for the reduction of p-nitrophenol into p-aminophenol by NaBH4, maintaining more than 97% of catalytic conversions compared to free Pt NPs as well as commercial Pt/C catalyst.
CuGaS2 hollow spheres from Ga–CuS core–shell nanoparticles
Ultrasonics Sonochemistry 21 (2014) 1194–1199
A liquid gallium emulsion was prepared as a starting material using ultrasound treatment in ethylene glycol. Core–shell particles of Ga@CuS were successfully synthesized by deposition of a CuS layer on gallium droplets through sonochemical deposition of copper ions and thiourea in an alcohol media. The core and shell of Ga@CuS products were composed of amorphous gallium metal and covellite phase CuS, which transformed into chalcopyrite CuGaS2 hollow spheres after sulfurization at 450C, which was the lowest crystallization temperature. The formation of hollow nanostructures was ascribed to the Kirkendall mechanism, in which liquid gallium particles play an important role as reactive templates. In conclusion, we obtained CuGaS2 hollow spheres with a 430 nm outer diameter and 120 nm shell thickness that had the same crystal structure and electrical properties as bulk CuGaS2.
Immobilization of Gd(III)-DOTA Complexes in Layered Double Hydroxides Thin Film
Bull. Korean Chem. Soc. 2013, Vol. 34, No. 11
the Gd(III) ion complexes of DOTA as a macrocyclic ligand were immobilized in the interlayer spaces of the LDH films by an intercalation reaction using an ethanol/toluene mixture, in which the pre-intercalated DOTA ligand in the LDH was able to chelate the Gd(III) ions. The XRD and the FT-IR results confirmed the successful exchange of the DOTA ligand with the carbonate ions in the pristine LDH film and the solid-state chelation of Gd(III) ions with the ligands. The current study can be extended to fabricate new hybrid films for the development of optoelectric devices containing lanthanide ions.
Topochemical Oxidation of Transition Metals in Layered Double Hydroxides by Anthraquinone-2-sulfonate
Bull. Korean Chem. Soc. 2012, Vol. 33, No. 2 725–727
highly crystalline Co2+ (or Ni2+)-Fe3+-LDHs have been synthesized using a unique topochemical oxidation
process by AQS2, which also functioned as intercalative moieties during a course of homogeneous precipitation of the metal hydroxides. The AQS2 played a key role in the oxidative intercalation process to produce the highly crystalline Fe3+-containing LDHs. A strong intermolecular interaction of the AQS2 guests in the interlayer spaces of LDH could prevent a structural deformation of the crystalline hydroxide layers during the oxidation process of Fe2+. This synthetic strategy could be extended to prepare other important series of transition-metal LDHs in various M2+/Fe3+ ratios such as Co2+-Fe2+-Fe3+-LDH, Ni2+-Fe2+-Fe3+-LDH and Fe2+-Fe3+-LDH for pure spinel ferrites.
Magnetic Properties of Thiol-capped Gold Nanoparticles
Journal od the Korean Physical Society, Vol. 60, No. 7, April 2012, pp. 1078–1081
We present the experimental results of magnetization measurements on thiol-capped gold nanoparticles (Au-SR NPs) synthesized in a two-phase liquid-liquid system. The size of particles ranged from 2.0 to 3.5 nm with an average size of 2.8 nm. The magnetic properties of Au-SR NPs were characterized by a mixture of ferromagnetic, paramagnetic and diamagnetic components. Magnetization curves showed the hysteresis behavior typical of a ferromagnet over the whole temperature (T) range investigated (2 K to 300 K) whereasM(H) did not saturate, not even at lowT, implying the existence of a paramagnetic component. The negative slope of M(H) observed at high T demonstrated that a diamagnetic component was also considerable. From a theoretical fit, we obtained effective values of parameters such as the paramagnetic effective moment,µp = 5.7 µB, and the diamagnetic susceptibility, χd = −1.7×10-7 emu/gOe. In addition, the T-dependence of the ferromagnetic componentMf(T) was extracted from the experimentalM(T), and its characteristics are discussed in the light of the mean field model.
Electrostatic spray-deposited CuInGaSe2 nanoparticles: Effects of precursors’ Ohnesorge number, substrate temperature, and flowrate on thin film characteristics
Journal of Aerosol Science 54 (2012) 1–12
The effect of precursor viscosity, substrate temperature, and flow rate on CuInGaSe2 nanoparticle-based thin films deposited by an electrostatic spray deposition (ESD) technique are studied. ESD is superior to pneumatic spraying because it produces nanoscale, self-dispersive (non-agglomerating), highly wettable (electrowetting) and adhesive droplets, which collectively yield a uniform coating on the substrate. The synthesized CuInGaSe2 nanoparticles were added to 4 different solvents: ethanol (E), butyl carbitol (BC), ethylene glycol (EG), and diethylene glycol (DEG). Subsequently, the solvents were electrostatically sprayed onto a molybdenum-coated soda-lime glass substrate. The solvent that yielded the most uniform surface morphology for the coated materials was identified. The surface roughness of the coated CIGS thin film, which depends on viscosity and the substrate temperature, was studied by AFM characterization.
Highly oriented nanoplates of layered double hydroxides as an ultra slow release system
Chem. Commun., 2012, 48, 5641–5643
A novel controlled molecular release based on highly oriented nanoplates of layered double hydroxide was fabricated on indium tin oxide substrates by electrophoretic deposition of exfoliated LDH nanosheets. The LDH particle coating exhibited a superior release performance of the order of hours.
A New Mussel-Inspired Polydopamine Sensitizer for Dye-Sensitized Solar Cells: Controlled Synthesis and Charge Transfer
Chem. Eur. J. 2012, 18, 14000–14007
The efficient electron injection by direct dye-to-TiO2 charge transfer and strong adhesion of mussel-inspired synthetic polydopamine (PDA) dyes with TiO2 electrode is demonstrated. Spontaneous self-polymerization of
dopamine using dip-coating (DC) and cyclic voltammetry (CV) in basic buffer solution were applied to TiO2 layers under a nitrogen atmosphere, which offers a facile and reliable synthetic pathway to make the PDA dyes, PDA-DC and PDA-CV, with conformal surface and perform an efficient dye-to-TiO2 charge transfer. Both synthetic methods led to excellent photovoltaic results and the PDA-DC dye exhibited larger current density and efficiency values than those in the PDACV dye. Under simulated AM 1.5 G solar light (100 mWcm-2), a PDA-DC dye exhibited a short circuit current density of 5.50 mWcm-2, corresponding to an overall power conversion efficiency of 1.2 %, which is almost 10 times that of the dopamine dye-sensitized solar cell. The PDA dyes showed strong adhesion with the nanocrystalline TiO2 electrodes and the interface engineering of a dye-adsorbed TiO2 surface through the control of the coating methods, reaction times and solution concentration maximized the overall conversion efficiency, resulting in a remarkably high efficiency.
Ultrasound-Induced Rapid Intercalation of Biselenite in Layered Double Hydroxides
Eur. J. Inorg. Chem. 2011, 3334–3339
The deintercalation of carbonate (CO32–) ions from MgAllayered double hydroxides (LDHs) (Mg/Al = 2) both in monolayer films and powdered samples under atmospheric conditions in ethanol was investigated. A selenous acid precursor was incorporated into the interlayer gallery. Treatment with 0.5M selenous acid (H2SeO3) for 30 min with powdered LDHs or with 0.1M H2SeO3for 5 min with the thin film LDHs resulted in carbonate ions being exchanged with biselenite (HSeO3–) ions. Electron microscopy showed that the morphologies of the original LDH particles remained after the reaction, despite the ultrasound being continuously applied for up to 2 h. XRD, FTIR and Raman spectroscopic scattering results strongly suggested that cyclic dimers of biselenite ions were incorporated into the gallery spaces of the LDHs, vertically arranged to the horizontal axes of the MgAl-LDH
Solvothermal Synthesis of Copper Indium Diselenide in Toluene
Bull. Korean Chem. Soc. 2011, Vol. 32, No. 2
Polycrystalline CuInSe2(CIS) was synthesized through solvothermal reactions in toluene with selected alkyl amines as complexing agents. The alkyl amines were used as reducing agent of selenium and catalytic ligands, enhancing the formation of CIS compounds in the colloidal solution. Toluene does not contribute the syntheses directly but minimizes the amounts of amines required for single phase CIS. We systematically studied the reactivity of amine compounds for the solovothermal syntheses, determined critical concentration of amine and the shortest reaction time. Crystallinity, morphology, chemical composition, and band gap of the prepared CuInSe2were respectively measured by X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy and UV-vis spectroscopy.
Platinum Nanoparticles Encapsulated by Aminopeptidase: A Multifunctional Bioinorganic Nanohybrid Catalyst
Angew. Chem. Int. Ed. 2011, 50, 11924–11929
When platinum nanoparticles are encapsulated by a bacterial aminopeptidase, the novel hybrid combines platinum-catalyzed hydrogenation and peptidase-catalyzed hydrolysis for multistep synthesis (see picture). This concept of bioinorganic integration can be extended to various enzymes and inorganic materials, allowing for the design and fabrication of novel multifunctional materials.
Large-Scale, Surfactant-Free Solution Syntheses of Cu(In,Ga)(S,Se)2 Nanocrystals for Thin Film Solar Cells
Eur. J. Inorg. Chem. 2011, 647–651
Large-scale (as much as 200 g in a batch) and surfactant-free syntheses of the CuInxGa1–xSe2and the CuInxGa1–xS2nanoparticles were investigated by employing a sonochemical process under ambient conditions. This synthetic approach eliminates the need for organic stabilizers, which may act as an insulator in the final device, and reduces the number of reaction steps for synthesis of high-quality CISe nanocrystals. We also demonstrate the solution-based fabrication of the thin film photovoltaic devices with a conversion effi ciency of 2.62 % by using nanocrystal-based inks. The device was fabricated with 2μm of a CIGS absorber layer on Mocoated soda lime glass, 70 nm of a chemical-bath-deposited CdS layer, 100 nm of an intrinsic ZnO layer, followed by 800 nm of a Al-doped ZnO layer. Finally, a patterned Ag (200 nm) grid was deposited on the top of the device. The current results offer a promising alternative for solutionbased CIGSe thin film solar cells, with a higher efficiency.
Electrochemical growth of synthetic melanin thin films by constant potential methods
Electrochimica Acta 56 (2011) 2954–2959
Polymerized melanin thin films were electrochemically synthesized in a 5,6-dihydroxyindole precursor solution on indium tin oxide (ITO) substrates using the cyclic voltammetry and constant potential methods. Tris(hydroxymethyl)aminomethane (THAM) and phosphate buffer solutions were applied to prepare the films that were well deposited to the ITO substrates. The films that were synthesized in the THAM buffer solution exhibited a faster growth rate and better adhesion to the ITO electrodes than the films in the phosphate buffer. The film thickness linearly increased at the growth rate of 0.8 nm/s as the deposition time and number of cycles increased. Two electrochemical conditions produced similar thicknesses as well as physical properties in each buffer solution. However, the constant potential method demonstrated that this provides the synthetic advantages of faster deposition and less consumption of electric charge compared to the cyclic voltammetry route.
Bimetallic nanoparticles of copper and indium by borohydride reduction
Thin Solid Films 519 (2011) 2176–2180
This study investigated the preparation of copper–indium bimetallic nanoparticles through the borohydride
reduction in an alcohol solution for application in ink-coating and sputtering target materials. Copper, indium metal and copper–indium intermetallic materials were synthesized by reacting CuCl2and InCl3with NaBH4 in 2-propanol (IPA) and tetraethylene glycol (TEG) at room temperature. The Cu–In samples contained Cu2In and CuIn phases with particle sizes of 10–100 nm and 30–200 nm in both the IPA and TEG solutions, respectively. The nanoparticulate Cu–In precursor layer was coated onto a soda-lime glass through spincasting, where the Cu–In intermetallic phases of Cu2In and Cu11In9were produced through heat treatment in Ar gas and a microstructured CuInSe2 layer was produced in a selenium atmosphere. Cu, In, Cu–In intermetallic nanoparticles and the films were characterized using powder X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analyses.
Anthraquinone Sulfonate Modified, Layered Double Hydroxide Nanosheets for Dye-Sensitized Solar Cells
Chem. Eur. J. 2010, 16, 8296–8299
a new hybrid light sensitizer was investigated based on employing the LDH nanosheets as an inorganic matrix to stabilize the AQS organic sensitizer in the DSCs. The LDHAQS nanosheets showed a conspicuous photochromic property under irradiation. This hybrid sensitized cell showed improved conversion efficiency up to 160 % of
the initial value compared with the AQS-sensitized cell.
Polymorphs of Pentacene and 6,13-Pentacenequinone in Solution and Vapor Phase Growths
Bull. Korean Chem. Soc. 2010, Vol. 31, No. 8
A new polymorph of PQ-S was demonstrated for the first time. This poly morph was grown in solution through the oxidation of PEN, Creating a zigzag structure that was titled by 21 with respected to a-axis. The PQ-V crystal has a packing structure similar to thin-film phase, where oxygen was a critical factor in determining the molecular packing.
Gold nanostructures on chemically reinforced PDMS microwell arrays
Applied Surface Science 256 (2010) 2066–2072
This paper describes a facile strategy for fabricating arrays of two- and three-dimensional gold nanostructures using PDMS-infiltrated polystyrene (PS) colloidal crystals. PDMS molding of colloidal crystal, gold vapor deposition, and subsequent calcination of PS produced gold thin layers over hexagonal PDMS microwell arrays with hemispherical air-voids of approximately 140 nm on glass substrates. Vapor deposition of perfluoroalkylsilane thin layers improved the thermal stability of the colloidal template over 1008C, providing a route to preparation of hollow architectures with gold thin layers supported by PDMS nanostructures. Surface modification of the PDMS using poly(allylamine hydrochloride) induced two-dimensional colloidal crystals of PS and PMMA spheres through electrostatic interactions. Particle aggregation of 13 nm gold nanoparticles in the PDMS microwells demonstrated a surface plasmon resonance band red-shifted to 810 nm, in comparison with that on the flat surface at 720 nm.