The Golden Fig: A Plasmonic Effect Study of Organic-Based Solar Cells

An optimization work on dye-sensitized solar cells (DSSCs) based on both artificial and natural dyes was carried out by a fine synthesis work embedding gold nanoparticles in a TiO2 semiconductor and perfecting the TiO2 particle sizes of the scattering layer. Noble metal nanostructures are known for the surface plasmon resonance peculiarity that reveals unique properties and has been implemented in several fields such as sensing, photocatalysis, optical antennas and PV devices. By embedding gold nanoparticles in the mesoporous TiO2 layer and adding a scattering layer, we were able to boost the power conversion efficiency (PCE) to 10.8%, using an organic ruthenium complex. The same implementation was carried out using a natural dye, betalains, extracted from Sicilian prickly pear. In this case, the conversion efficiency doubled from 1 to 2% (measured at 1 SUN illumination, 100 mW/cm2 under solar simulation irradiation). Moreover, we obtained (measured at 0.1 SUN, 10 mW/cm2 under blue light LED irradiation) a record efficiency of 15% with the betalain-based dye, paving the way for indoor applications in organic natural devices. Finally, an attempt to scale up the system is shown, and a betalain-based- dye-sensitized solar module (DSSM), with an active area of 43.2 cm2 and a PCE of 1.02%, was fabricated for the first time.

Spatial Distribution of Sound Scattering Layer and Density Estimation of Euphausia pacifica in the Center of the Yellow Sea Bottom Cold Water Determined by Hydroacoustic Surveying

The Yellow Sea Bottom Cold Water (YSBCW) refers to seawater with a water temperature of 10 °C or less found at the bottom of the center of the Yellow Sea. The spatiotemporal variability of the YSBCW directly affects the distribution of organisms in the marine ecosystem. In this study, hydroacoustic and net surveys were conducted in April (spring) to understand the spatial distribution of the sound scattering layer (SSL) and estimate the density of Euphausia pacifica (E. pacifica) in the YSBCW. Despite the shallow water in the YSBCW region, E. pacifica formed an SSL, which was distributed near the bottom during the daytime; it showed a diel vertical migration (DVM) pattern of movement toward the surface during the nighttime. The mean upward and downward swimming speeds around sunset and sunrise were approximately 0.6 and 0.3–0.4 m/min, respectively. The E. pacifica density was estimated in the central, western, and eastern regions; the results were approximately 15.8, 1.3, and 10.3 g/m2, respectively, indicating significant differences according to region. The results revealed high-density distributions in the central and eastern regions related to the water temperature structure, which differs regionally in the YSBCW area. Additional studies are needed regarding the spatial distribution of E. pacifica in the YSBCW and its relationship with various ocean environmental parameters according to season. The results of this study contribute to a greater understanding of the structure of the marine ecosystem in the YSBCW.

Scattering Attenuation of the Martian Interior through Coda-Wave Analysis

ABSTRACT We investigate the scattering attenuation characteristics of the Martian crust and uppermost mantle to understand the structure of the Martian interior. We examine the energy decay of the spectral envelopes for 21 high-quality Martian seismic events from sols 128 to 500 of InSight operations. We use the model of Dainty, Toksöz, et al. (1974) to approximate the behavior of energy envelopes resulting from scattered wave propagation through a single diffusive layer over an elastic half-space. Using a grid search, we mapped the layer parameters that fit the observed InSight data envelopes. The single diffusive layer model provided better fits to the observed energy envelopes for high-frequency (HF) and very-high-frequency (VF) than for the low-frequency and broadband events. This result is consistent with the suggested source depths (Giardini et al., 2020) for these families of events and their expected interaction with a shallow scattering layer. The shapes of the observed data envelopes do not show a consistent pattern with event distance, suggesting that the diffusivity and scattering layer thickness is nonuniform in the vicinity of InSight at Mars. Given the consistency in the envelope shapes between HF and VF events across epicentral distances and the trade-offs between the parameters that control scattering, the dimensions of the scattering layer remain unconstrained but require that scattering strength decreases with depth and that the rate of decay in scattering strength is the fastest near the surface. This is generally consistent with the processes that would form scattering structures in planetary lithospheres.

Broadband Characteristics of Zooplankton Sound Scattering Layer in the Kuroshio–Oyashio Confluence Region of the Northwest Pacific Ocean in Summer of 2019

Acoustic technology, as an important investigation method for fishery resources, has been widely used in zooplankton surveys. Since the Kuroshio–Oyashio confluence region has an extensive distribution of zooplankton, describing and analyzing the characteristic of the zooplankton sound scattering layer (SSL) in this area is essential for marine ecology research. To understand its spatial–temporal distribution, acoustic data of the Kuroshio–Oyashio confluence region at the Northwest Pacific Ocean, obtained by a Simrad EK80 broadband scientific echosounder in 2019, were used on board the research vessel (RV) Songhang. After noise removal, the volume backscattering strength (SV) was measured to plot the broadband scattering spectrogram of each water layer and to exhibit zooplankton distribution. The results show that the main sound scattering within 0–200 m originate from the zooplankton, and the SV of each layer increases with the rise of the transducer frequency. The magnitude of SV was closely synchronized with the solar altitude angle, which gets smaller when the angle is positive, then larger when the angle is negative. It means that the SSL has a diel vertical migration (DVM) behavior with the variation of solar height. Meanwhile, scattering strength was positively correlated with temperature in the vertical direction and showed a maximum of −54.31 dB at 20–40 m under the influence of the thermocline. The Kuroshio and Oyashio currents had an obvious influence on the scattering strengths in this study, indicating a low value when next to the Oyashio side and a high value on the Kuroshio side. The scattering strength near the warm vortex center was higher than that at the vortex edge. The results of this study could provide references for a long-term study on ecological environment variation and its impacts on zooplankton distribution.

Efficiency Improvement in Dye-Sensitized Solar Cells by Modify Titanium Dioxide Formation on Supercritical Carbon Dioxide Fluid Synchronous Dyeing

In this study, the dye sensitized solar cells (DSSC) were assembled by using natural dyes extracted from roselle and red phoenix as sensitizer coated fluorine-doped tin dioxide substrate (FTO) plate used a counter electrode for nanocrystalline TiO2. We investigated the formation of modified titanium dioxide on dye-sensitized solar cells by simultaneous dyeing with supercritical carbon dioxide fluid. The photoelectrode is made of compact layer and scattering layer. Supercritical carbon dioxide fluid extracted natural dyestuff and synchronous dyed photoelectric. The photoelectric conversion efficiency is the best at the dyeing parameters of 3000 psi, 50 ºC, and 30 minutes. Experimental results show that adding a scattering layer to the compact layer can improve the conversion efficiency. SEM can observe that the polyethylene glycol-added scattering layer has more pore structures in which improves the electrode’s ability to capture sunlight. The conversion efficiency of 0.13% can be obtained by using 9:1 mixed dyes of anthocyanin and chlorophyll. The photoelectric conversion efficiency with the P25/R-type/PEG scattering layer is about 30% higher than that of a single compact layer. Finally the paper proposes a schematic diagram of the dye-sensitized solar cell.

Mesoporous SiO2@TiO2 Core Shell Spheres for Light Scattering Layer in the Photoande of a Dye-Sensitized Solar Cell

Mesoporous SiO2@TiO2 (MP-SiO2@TiO2) core-shell particles were fabricated using mesoporous SiO2 particles as a template in order to improve scattering performance and dye adsorption performance of the photoanode of dye-sensitized solar cells (DSSCs). They were used to make the scattering layer of the photoanode. Commercially available submicron TiO2 particles G1 that have the same particle size as the fabricated SiO2@TiO2 particles were also used to make the scattering layer to compare the photoelectric properties of the DSSC. The DSSC with the photoanode without a scattering layer generated a conversion efficiency of 1.54 %. By introducing a scattering layer composed of MP-SiO2@TiO2 to the photoanode, the conversion efficiency was improved to 2.82 %. In addition, the DSSC with the scattering layer composed of MP-SiO2@TiO2 generated higher conversion efficiency than that of the DSSC with the scattering layer composed of G1 (2.35 %). From these results, MP-SiO2@TiO2 particles produced a high performance as scatterers in the photoanode of DSSCs.

Imaging with Local Speckle Intensity Correlations: Theory and Practice

Recent advances in computational imaging have significantly expanded our ability to image through scattering layers such as biological tissues by exploiting the auto-correlation properties of captured speckle intensity patterns. However, most experimental demonstrations of this capability focus on the far-field imaging setting, where obscured light sources are very far from the scattering layer. By contrast, medical imaging applications such as fluorescent imaging operate in the near-field imaging setting, where sources are inside the scattering layer. We provide a theoretical and experimental study of the similarities and differences between the two settings, highlighting the increased challenges posed by the near-field setting. We then draw insights from this analysis to develop a new algorithm for imaging through scattering that is tailored to the near-field setting by taking advantage of unique properties of speckle patterns formed under this setting, such as their local support. We present a theoretical analysis of the advantages of our algorithm and perform real experiments in both far-field and near-field configurations, showing an order-of magnitude expansion in both the range and the density of the obscured patterns that can be recovered.