We investigate the fluorescence from dyes coupled to individual DNA-functionalized metal nanoparticles. use single-particle darkfield scattering and microscopy correlate intensity of with localized surface plasmon resonance (LSPR) spectra nanoparticles which they are attached. For each three different dyes, we observe a strong correlation between dye degree spectral overlap nanoparticle. On average, brightest attached that have LSPR peak ∼40−120 meV higher in energy than emission...

We use photoinduced absorption spectroscopy to measure long-lived photogenerated charge carriers in optically thin donor/acceptor conjugated polymer blend films near plasmon-resonant silver nanoprisms. up 3 times more generation, as judged by the magnitude of polaron signal, 35 nm poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester on top nanoprisms (∼40−100 edge length). find that yields increase linearly with total sample extinction. These excitation enhancements could principle be...

The near-field effects of plasmonic optical antennas are being explored in applications ranging from biosensors to solar cells. We demonstrate that photoluminescence emission enhancement CdSe quantum dots (QDs) can be obtained the absence any excitation near single silver nanoprisms. spectral dependence radiative and nonradiative decay rate QDs closely follows nanoparticle plasmon scattering spectrum. Using both experiment theory we show that, enhancement, ratio is proportional efficiency....

We describe local (∼150 nm resolution), quantitative measurements of charge carrier mobility in conjugated polymer films that are commonly used thin-film transistors and nanostructured solar cells. measure space limited currents (SCLC) through these using conductive atomic force microscopy (c-AFM) macroscopic diodes. The current densities we with c-AFM substantially higher than those observed planar devices at the same bias. This leads to an overestimation by up 3 orders magnitude when...

We study plasmon-enhanced fluorescence from CdSe∕CdS∕CdZnS∕ZnS core/shell quantum dots near a variety of Ag and Au nanoparticles. The photoluminescence excitation (PLE) spectrum closely follows the localized surface plasmon resonance (LSPR) scattering measure enhancement factors ∼3 to 10 for different shapes single metal

Plasmonic metal nanoparticles have been used to enhance the performance of thin-film devices such as organic photovoltaics based on polymer/fullerene blends. We show that silver nanoprisms accumulate long-lived negative charges when they are in contact with a photoexcited bulk heterojunction blend composed poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM). report both charge modulation and electroabsorption spectra solid-state compare these photoinduced absorption...

We study the homogeneous line width of plasmon resonance scattering peaks anisotropic silver nanoparticles using single particle darkfield spectroscopy. correlate spectra with scanning electron microscopy images particles to investigate effects nanoparticle size on width. observe that widths nanoprisms increase both as volume increases and energy increases. attribute dependence radiation damping compare our data simple dipole-limit approximations for radiative nonradiative decay rates...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

Coupled plasmonic/chromophore systems are of interest in applications ranging from fluorescent biosensors to solar photovoltaics and photoelectrochemical cells because near-field coupling metal nanostructures can dramatically alter the optical performance nearby materials. We show that CdSe quantum dots (QDs) near single silver nanoprisms exhibit photoluminescence lifetimes yields depend on excitation wavelength, apparent violation Kasha–Vavilov rule. attribute variation QD lifetime with...

Reduced-dimensionality materials for photonic and optoelectronic applications including energy conversion, solid-state lighting, sensing, information technology are undergoing rapid development. The search novel based on reduced-dimensionality is driven by new physics. Understanding optimizing material properties requires characterization at the relevant length scale, which often below diffraction limit. Three important systems chosen review here, all of under investigation Molecular...

We investigate a plasmonic resonant structure tunable from ultra-violet to near infrared wavelengths with maximum absorbance strength over 95% due highly efficient coupling incident light. Additional harmonics are excited at higher frequencies extending the range multiple wavelengths. propose concept of black metal nanoresonator that exhibits broadband characteristics by spacing modes closer through increasing resonator length and employing adiabatic nano-focusing on tapered end cavity.

Abstract One of the major challenges to widespread adoption plasmonic and nano-optical devices in real-life applications is difficulty mass-fabricate antennas parallel reproducible fashion, capability precisely place nanoantennas into with nanometer-scale precision. In this study, we present a solution challenge using state-of-the-art ultraviolet nanoimprint lithography (UV-NIL) fabricate functional optical transformers onto core an fiber single step, mimicking ‘campanile’ near-field probes....

Tip-enhanced photoluminescence (TRPL) is a powerful technique for spatially and spectrally probing local optical properties of 2-dimensional (2D) materials that are modulated by the heterogeneities, revealing inaccessible dark states due to bright state overlap in conventional far-field microscopy at room temperature. While scattering-type near-field probes have shown potential selectively enhance reveal exciton emission, their technical complexity sensitivity can pose challenges under...

Integration of complex photonic structures onto optical fiber facets enables powerful platforms with unprecedented functionalities. Conventional nanofabrication technologies, however, do not permit viable integration devices fibers owing to their low throughput and high cost. In this paper we report the fabrication a three-dimensional structure achieved by direct nanoimprint lithography on facet an fiber. Nanoimprint processes tools were specifically developed enable lithographic accuracy...

We describe the phase transfer of large, anisotropic, silver nanoparticles (approximately 50-100 nm edge length) from water to polar organics such as alcohols, acetone, dimethylformamide and nonpolar hexanes. transferred organic solvents via their precipitation in by centrifugation redispersion organics. Using scanning electron microscopy (SEM) imaging UV-vis extinction spectra, we confirmed that there was little no shape change upon solvents. The were stable for months also hexanes with up...

In this Letter, we present a Fresnel lens fabricated on the end of an optical fiber. The is using nanoimprint lithography functional high refractive index material, which suitable for mass production. main advantage presented compared to conventional fiber its (n=1.68), enables efficient light focusing even inside other media, such as water or adhesive. Measurement performance in immersion liquid (n=1.51) shows near diffraction limited focal spot 810 nm diameter at 1/e2 intensity level...

A novel method to realizing printed active photonic devices was developed using nanoimprint lithography (NIL), combining a printable high-refractive index material and colloidal CdSe/CdS quantum dots (QDs) for applications in the visible region. Active media QDs were applied two different ways: embedded inside matrix form an hybrid nanocomposite, used as uniform coating on top of devices. As proof-of-demonstration devices, two-dimensional (2-D) crystals well 1D 2D nanocavities successfully...

We apply a combination of photoswitch-modified DNA and AFM-based pulling measurements to study the force-induced melting double-stranded in unzipping geometry. measure differences peak rupture force for azobenzene-modified DNA, as incorporated azobenzenes are photoswitched reversibly between trans cis form. Fitting our versus loading rate data, we obtain off (koff) at zero values range ∼10 s(-1). show that change koff induced by destabilizing duplex depends on position azobenzene photoswitch...

The extraction of scintillation light from a crystal with high efficiency and low time jitter is vital for realizing much-needed gains in the performance numerous radiation detection imaging instruments that are components medical imaging, industrial, homeland security applications detection, localization, energy classification X-rays, γ-rays, or neutrons. Nanostructures such as photonic crystals (PhCs) maximize usable otherwise lost when refractive index (RI) scintillator coupled to...

Abstract New sources of clean water are currently being researched and implemented, to face global shortage. Techniques such as desalination or cloud seeding can have a high yield but present problems excessive energy consumption consistent environmental impacts. Fog harvesting stands out for considerably simpler inexpensive compared the previous. In last decades researchers developed detailed studies numerical models, supported by number successful examples located mainly in arid seasonally...

Nanoimprint lithography (NIL) of functional high-refractive index materials has proved to be a powerful candidate for the inexpensive manufacturing high-resolution photonic devices. In this paper, we demonstrate fabrication printable crystals (PhCs) with high refractive working in visible wavelengths. The PhCs are replicated on titanium dioxide-based hybrid material by reverse NIL almost zero shrinkage and high-fidelity reproducibility between mold printed optical responses imprinted compare...