Optically-enhanced performance of polymer solar cells with low concentration of gold nanorods in the anodic buffer layer

In this work, the effect of gold nanorods on the performance of poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric-acid-methyl-ester bulk heterojunction solar cells was investigated. Gold nanorods were introduced into the anodic buffer layer by simply blending them with the solution of poly(3,4-ethyl enedioxythiophene):poly(styrenesulfonate). Even with a fairly low density of the nanorods, the resulting devices showed a remarkable 21.3% enhancement in the power conversion efficiency and a 13% enlargement in the short circuit current. By examining the absorbance profiles of active films made with different conditions,\ud such enhancements can be related to the localized transverse and longitudinal plasmon resonance modes in the metallic nanoparticles. Gold nanorods helped as well in reducing the device series resistance by up to 36%, which also contributed to the global enhancement in the efficiency

Low density of gold nanorods in the anodic layer for enhancing the efficiency of organic solar cells

The effect of using an anodic layer with low density (~ 6x108 cm-2) of gold nanorods (GNR) in organic bulk heterojunction poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) solar cells was studied. GNRs were deposited using several techniques, which produced various densities of GNRs on the anode layer. The anodic layers were characterized microscopically and spectroscopically. The power conversion efficiency and the short-circuit current for experimental devices incorporating GNR anodic layer showed an enhancement of up to 18% as compared to the control device. The results suggest that the electric field in the P3HT:PCBM active layer was increased by the localized surface plasmon resonances in GNRs. The increase in the electric field enhanced the photo-generation of excitons in the active layer near the plasmon peak, which improved the short-circuit current and the overall power conversion efficiency. Interestingly, photovoltaic devices with a low density of GNRs in the anodic layer showed an increase in the power conversion efficiency that was superior to that of devices with a higher density of GNRs in the anodic layer. This suggests that although the anodic layer with a higher density of GNRs absorbed more light, part of this light was confined in the anodic layer itself, and prevented from reaching the active layer of the bulk heterojunction device. In such cases, the power conversion efficiency was even found to be decreased with respect to the value for the control device

Solar Energy and Solar Cells

Thanks to the helpful discussions and strong support provided by the Publisher and Editorial Staff of Nanomaterials, I was appointed as a section Editor-in-Chief of the newly launched section “Solar Energy and Solar Cells” earlier this year (2021) [...

Hollow, branched and multifunctional nanoparticles : Synthesis, properties and applications

Nanoscale materials with various structures have attracted extensive research interest during the past decade. Among them, hollow, branched and multifunctional nanoparticles comprised of two different nanoparticle components are emerging as new classes of interesting nanomaterials owing to the unique optical, catalytic, electrical, magnetic and mechanical properties associated with their unusual morphologies as well as their potential wide range of applications in various fields such as photothermal therapy, diagnosis, drug delivery, catalysis, optoelectronic, electronics and biodiagnostics. In particular, branched nanoparticles promise to serve as building blocks for more complex materials and advanced devices through self-assembly and self-alignment and heterodimeric nanoparticles show promise for the development of tunable magnetic materials and multimodal biodiagnostic imaging tools.Peer reviewed: YesNRC publication: Ye

A new approach towards controlled synthesis of multifunctional coreshell nano-architectures: luminescent and superparamagnetic

We have developed a two-step method for synthesis of multifunctional core-shell nanoparticles with an improved structure as compared with those prepared by traditional methods used independently. The nanoparticles comprise a superparamagnetic core, an inner insulating dye-free silica shell, an outer luminescent silica shell encapsulating thousands of dye molecules and a functionalizeable surface. The innovative insertion of the isolating silica shell benefits the nanoparticles' architecture in two ways. Firstly, by keeping the dye molecules away from the magnetic core, the silica shell prevents dye luminescence quenching. Secondly, the non-magnetic shell decreases magnetic interparticle coupling, which, by reducing aggregation and preventing agglomeration, facilitates the formation of the high-quality luminescent shell in the second step of the process. The final nanoparticles being both superparamagnetic and luminescent have a great potential for theranostic applications such as ultra-sensitive detection, and in-vitro and in-vivo imaging.NRC publication: Ye

Advances in Lithium−Oxygen Batteries, Indoor Organic Photovoltaics, and Perovskite Photocatalysis

Multifaceted energy research is making rapid progress in exploring new materials for energy conversion and storage. This Energy Spotlight features three recent articles of interest to our energy research community. Editorial advisory board members Jun Lu, Dongling Ma, and Iván Mora-Seró present article highlights on controlling superoxide reactions in lithium–oxygen batteries, the material design for indoor organic photovoltaics, and metal halide perovskites for photocatalytic applications. The article by Huang et al. was also selected for ACS Editors’ Choice and remains one of the most-read articles of the month

Evolution Characteristics and Causes—An Analysis of Urban Catering Cluster Spatial Structure

Studying the development characteristics of the urban catering industry holds significant importance for understanding the spatial patterns of cities. In this manuscript, according to the characteristics of the distribution of catering points and based on catering point of interest (POI) data of 106 cities in China in 2016 and 2022, we propose the Natural Nearest Neighbor Single Branch Model (NNSBM) to identify catering points by adaptive clustering, which improves the efficiency of identifying catering clusters. Subsequently, a catering spatial structure division model is constructed to classify the spatial structure of catering clusters into 3 major categories and 17 subcategories, and the evolution pattern of urban catering clusters is analyzed. In addition, based on the population density raster data, a bivariate spatial autocorrelation model is employed to analyze the complex relationship between the distribution of urban catering clusters and population density, revealing the distinctive characteristics of urban catering cluster evolution. The results showed that (1) In the initial stage of catering cluster formation, catering activities tend to gather first in a specific area of the city, giving rise to the main catering cluster. However, as the catering industry progresses, the phenomenon of “central fading” occurs within the main catering cluster. (2) The overall trend of the catering spatial structure of most cities showed an evolution toward low primacy–high concentration (Lp-Hc), and cities at different stages of catering capacity exhibited different evolution characteristics of catering clusters. (3) The influence of population density on catering distribution was staged, with a varying impact on cities with different types of catering spatial structures

Analysis of Spatio-Temporal Evolution of Regional Settlements under the Background of Rapid Urbanization: A Case Study in Sishui County, China

China’s urbanization has achieved rapid development in the past 20 years, with towns expanding in size and the population increasing, while rural society has also undergone dramatic changes. An in-depth study on the evolution process of rural settlements in the context of rapid urbanization is beneficial to the rational planning of villages and the promotion of green and sustainable urban development. Located in East China, Sishui County is in the transition area between three types of landforms: hills, plains, and mountains. The spatial distribution of rural settlements in the urbanization process shows obvious regional differences. To our best knowledge, research on the spatio-temporal evolution of regional settlements in Sishui County is rare. In this study, we chose Sishui County as the study area, utilized Landsat5 (TM) and Landsat8 (OLI) satellite data as remote sensing data sources, and applied Geographic Information System (GIS) spatial analysis methods, central place theory, and core–periphery theory to explore the evolution process for the pattern, scale, and structure of rural settlements in this region from 2000 to 2021 and to investigate the influencing factors. The results show that: (1) in terms of the evolution of the rural settlement pattern, its distribution shows a gradual increase in the degree of dispersion, which indicates an overall development trend in the region of Sishui County in recent years and that the trend is gradually increasing; (2) in terms of scale evolution, the degree and speed of expansion in rural settlements of Sishui County have gradually decreased, and the scale grade has gradually increased; (3) in terms of structural evolution, the hierarchy system in rural settlements of Sishui County is constantly being improved and optimized from a simple to a complex core–periphery structure. These results will provide data support for the rational planning of villages and sustainable, high-quality urban development. They will also help local governments take appropriate measures to achieve coordinated and sustainable socio-economic and environmental development in the region