Electrically induced electron spin polarization is imaged in n-type ZnSe epilayers using Kerr rotation spectroscopy. Despite no evidence for an electrically internal magnetic field, current-induced in-plane observed with characteristic lifetimes that decrease doping density. The Hall effect also observed, indicated by out-of-plane opposite sign spins accumulating on edges of the sample. conductivity estimated as 3+/-1.5 Omega(-1) m(-1)/|e| at 20 K, which consistent extrinsic mechanism. Both...

Controllable biaxial and uniaxial nanowrinkles (see figure) are fabricated by a simple two-step approach — metal deposition subsequent heating based on shape memory polymer (prestressed polystyrene) sheets. The wavelengths of the wrinkles can be tuned controlling thickness deposited metal. ready integration into microchannels their effectiveness in surface enhanced sensing is demonstrated.

The performance of chemically synthesized lead sulfide (PbS) quantum dots (QDs) in planar, nontracking luminescent solar concentrators (LSCs) is evaluated using spectroscopic and photovoltaic techniques. Spatially resolved measurements are used to investigate analyze the role reduced self-absorption on LSC efficiency. From comparative samples with Rhodamine B CdSe/ZnS QDs it established that PbS LSCs generate nearly twice photocurrent silicon cells than other materials, achieving an...

Compared to bulk perovskites, charge transport in perovskite quantum dot (PQD) solids is limited. To address this issue, energetically aligned capping ligands were used prepare methylammonium lead bromide (MAPbBr3) PQDs toward enhancing surface carrier density PQD solids. Trans-cinnamic acid (TCA) and its derivates, functionalized with electron-donating or electron-withdrawing groups modulate energy levels, are as passivating exciton-delocalizing (EDLs) decrease the gap respect core....

Abstract Metal halide perovskites (MHPs) have emerged as a prominent new photovoltaic material combining very competitive power conversion efficiency that rivals crystalline silicon with the added benefits of tunable properties for multijunction devices fabricated from solution which can yield high specific power. Perovskites also demonstrated some lowest temperature coefficients and highest defect tolerance, make them excellent candidates aerospace applications. However, MHPs must...

We investigate the performance of cylindrical luminescent solar concentrators (CLSCs) with near-infrared lead sulfide quantum dots (QDs) in active region. fabricate solid and hollow cylinders from a composite QDs polymethylmethacrylate, prepared by radical polymerization, characterize sample homogeneity optical properties using spectroscopic techniques. additionally measure photo-stability photocurrent outputs under both laboratory external ambient conditions. The experimental results are...

The isotropic to nematic liquid crystal (LC) phase transition is used create organized assemblies of CdSe/ZnS core/shell quantum dots (QDs). Under controlled conditions, well dispersed QDs are expelled from the ordered domains LC into remaining domains. final produces three dimensional QD that situated at defect points in volume. Through luminescence we able track movement nanoparticles as formed spectrally probe resulting assemblies. Forster resonance energy transfer (FRET) measurements,...

Organic–inorganic hybrid perovskite (PVSK) compounds are at the forefront of photovoltaic research, consistently surpassing silicon solar cells in power conversion efficiency. Possessing high refractive index, broad absorption spectrum, and superior quantum yields, PVSK thin films theoretically also ideal candidates for luminescent concentrators (LSCs). In practice, however, possibility self‐absorption a continuous film, coupled with inherent instability materials, have hindered their use...

Time-resolved optical techniques are used to explore electron spin dynamics in bulk and epilayer samples of n-type ZnO as a function temperature magnetic field. The sample yields coherence time T2* 20 ns at T = 30 K. Epilayer samples, grown by pulsed laser deposition, show maximum 2 10 K, with precession persisting up 280

Abstract Mesogenic ligands have the potential to provide control over dispersion and stabilization of nanoparticles in liquid crystal (LC) phases. The creation such hybrid materials is an important goal for soft tunable photonic devices, as LC laser. Herein, we present a comparison isotropic mesogenic attached surface CdSe (core‐only) CdSe/ZnS (core/shell) quantum dots (QDs). ligand′s flexible arm structure enhances ligand alignment, with local director promoting QD nematic To characterize...

We demonstrate spectral and polarization modulation of chemically synthesized core-shell CdSe/ZnS quantum dots (QDs) embedded in a one-dimensional photonic cavity formed by cholesteric liquid crystal (CLC) matrix. A Cano-wedge cell varies the pitch CLC leading to formation Grandjean steps. This spatially tunes stop band, changing resonance condition continuously altering both emission wavelength state QD ensemble. Using high resolution spectrally resolved photoluminescence measurements, we...

We report our results of developing perovskite thin films with high coverage, improved uniformity and preserved crystalline continuity in a single pass deposition.

Water quality monitoring is essential for identifying risks to environmental and human health. Nitrate of particular importance, as its anthropogenic point nonpoint sources are common globally have deleterious effects on water usability well aquatic ecosystem Standard methods assessing nitrate concentrations in generally involve laboratory techniques, available field testing face significant tradeoffs between cost, precision, portability. Given relatively ubiquitous nature the widespread...

In recent years the dispersion and directed assembly of nano-particles in liquid crystal media has proved an interesting field for investigation one that may yield new hybrid materials optical applications fundamental research. this paper, we investigate quantum dots different phases, looking at aggregation pattern formation. Quantum dot self-assembly crystals is dependent on particle surface properties concentration medium. By varying these parameters observe some fascinating structures...

A new process for the generation of micron-scale vesicle-like nanoparticle shells is reported. These constructs consist a robust, thin spherical layer, composed closely packed quantum dots (QDs) and are stabilized by ligand–ligand interactions. This represents versatile method making non-planar 3D nano-assemblies.

Quantum dot/liquid crystal nano-composites are promising new materials for a variety of applications in energy harvesting, displays and photonics including the liquid laser. To realize many applications, however, we need to control stabilize nano-particle dispersion different host phases understand how particles behave an anisotropic fluid. An ideal system will allow controlled assembly either well-defined clusters or uniform particle distribution. In this paper, investigate...

In this work, we studied the effects of particles' size and temperature on photoluminescence (PL) CH3NH3PbBr3 perovskite nanocrystals (PNCs), with PNC controlled by varying surface passivating ligands. The structural optical properties PNCs were investigated using UV-Vis PL spectroscopy, revealing strong quantum confinement effects. Temperature dependent measurements showed spectral blue shift peak for small (3.1 ± 0.2 nm) decreasing from 300 K to 20 K, which is opposite red observed large-...

Abstract Organo‐metal halide perovskites (OMHPs) are currently one of the most exciting candidates for photovoltaics. However, their impact in other areas related to carrier photogeneration, such as luminescent solar concentrators (LSCs), has been limited. OMHP thin films have demonstrated encouraging results LSCs, but a scalable platform with minimal losses, discrete emitters preferable. Perovskite quantum dots (PQDs) possess higher photoluminescence yield (PLQY) than film counterparts, and...

Fiber-based Raman spectroscopy enhances the signal by maximizing overlap of optical field and gas species. However, filling hollow-core fiber (HCF) with requires time that is dependent on core diameter, length, pressure gas. At ambient pressure, uptake driven diffusion into ends, severely limiting response system. By laser drilling access holes to along length fiber, reduced, improving system time. In this work, we study carbon dioxide (CO 2 ) sensor dynamics based intensity generated in...

Surface functionalization of nanoscale materials has a significant impact on their properties. We have demonstrated the effect different passivating ligands crystal phase organometal halide perovskite quantum dots (PQDs). Using static and dynamic spectroscopy, we studied transitions in CH3NH3PbBr3 PQDs ligated with either octylaminebromide (P-OABr) or 3-aminopropyl triethoxysilane (P-APTES). Around 140 K, P-OABr underwent structural transition from tetragonal to orthorhombic, established by...

Organic–inorganic perovskites that combine the strength of both chemical worlds have emerged as tantalizing candidates for next generation photovoltaics. Here, electrohydrodynamically assisted continuous liquid interface propagation a general, and potentially scalable nanomanufacturing route toward synthesizing high quality perovskite thin films in rapid throughput fashion is reported. This strategy conceptually mimics advantageous self‐organizing features emulsion droplets where use binary...