Dispelling clichés at the nanoscale: the true effect of polymer electrolytes on the performance of dye-sensitized solar cells

Complete characterization of RNA biomarker fingerprints using a multi-modal ATR-FTIR and SERS approach for label-free early breast cancer diagnosis

Breast cancer is a prevalent form of cancer worldwide, and the current standard screening method, mammography, often requires invasive biopsy procedures for further assessment. Recent research has explored microRNAs (miRNAs) in circulating blood as potential biomarkers for early breast cancer diagnosis. In this study, we employed a multi-modal spectroscopy approach, combining attenuated total reflection Fourier transform infrared (ATR-FTIR) and surface-enhanced Raman scattering (SERS) to comprehensively characterize the full-spectrum fingerprints of RNA biomarkers in the blood serum of breast cancer patients. The sensitivity of conventional FTIR and Raman spectroscopy was enhanced by ATR-FTIR and SERS through the utilization of a diamond ATR crystal and silver-coated silicon nanopillars, respectively. Moreover, a wider measurement wavelength range was achieved with the multi-modal approach than with a single spectroscopic method alone. We have shown the results on 91 clinical samples, which comprised 44 malignant and 47 benign cases. Principal component analysis (PCA) was performed on the ATR-FTIR, SERS, and multi-modal data. From the peak analysis, we gained insights into biomolecular absorption and scattering-related features, which aid in the differentiation of malignant and benign samples. Applying 32 machine learning algorithms to the PCA results, we identified key molecular fingerprints and demonstrated that the multi-modal approach outperforms individual techniques, achieving higher average validation accuracy (95.1%), blind test accuracy (91.6%), specificity (94.7%), sensitivity (95.5%), and F-score (94.8%). The support vector machine (SVM) model showed the best area under the curve (AUC) characterization value of 0.9979, indicating excellent performance. These findings highlight the potential of the multi-modal spectroscopy approach as an accurate, reliable, and rapid method for distinguishing between malignant and benign breast tumors in women. Such a label-free approach holds promise for improving early breast cancer diagnosis and patient outcomes.

An Overview on Anodes for Magnesium Batteries: Challenges towards a Promising Storage Solution for Renewables

Magnesium-based batteries represent one of the successfully emerging electrochemical energy storage chemistries, mainly due to the high theoretical volumetric capacity of metallic magnesium (i.e., 3833 mAh cm-3 vs. 2046 mAh cm-3 for lithium), its low reduction potential (-2.37 V vs. SHE), abundance in the Earth's crust (104 times higher than that of lithium) and dendrite-free behaviour when used as an anode during cycling. However, Mg deposition and dissolution processes in polar organic electrolytes lead to the formation of a passivation film bearing an insulating effect towards Mg2+ ions. Several strategies to overcome this drawback have been recently proposed, keeping as a main goal that of reducing the formation of such passivation layers and improving the magnesium-related kinetics. This manuscript offers a literature analysis on this topic, starting with a rapid overview on magnesium batteries as a feasible strategy for storing electricity coming from renewables, and then addressing the most relevant outcomes in the field of anodic materials (i.e., metallic magnesium, bismuth-, titanium- and tin-based electrodes, biphasic alloys, nanostructured metal oxides, boron clusters, graphene-based electrodes, etc.).

Binary counter ion effects and dielectric behavior of iodide ion conducting gel-polymer electrolytes for high-efficiency quasi-solid-state solar cells

A series of highly efficient quasi-solid-state dye-sensitized solar cells (DSCs) is prepared by harnessing the binary cation effect and positive effects of the selected performance enhancers of gel-polymer electrolytes. The new electrolyte is composed of polyacrylonitrile polymer, tetra-hexylammonium iodide (Hex₄NI) and KI binary salts as well as 4-tertbutylpyridine and 1-butyl-3-methylimidazolium iodide performance enhancers. The charge transport in the series of electrolytes is thermally activated and, accordingly, the temperature dependence of conductivity follows the VTF behavior. The enhancement of conductivity is observed with an increasing mass fraction of KI and decreasing mass fraction of Hex₄NI, while the total mass fraction of salts in the electrolyte is kept unchanged. The highest conductivity of 3.74 mS cm^-1 at ambient temperature is shown by the sample containing KI only (without Hex₄NI) at all the temperatures. The effects of dielectric polarization of the electrolytes are studied by analyzing the frequency dependence of the real and the imaginary parts of the AC conductivity in detail. Appropriate and reproducible cell construction are assured by efficiencies of above 5% exhibited by all the quasi-solid-state DSCs assembled using double-layered TiO₂ photo-electrodes and the new electrolyte series. Besides, highlighting the mixed cation effect, the cells with mixed salts exhibited efficiencies greater than 6%. An impressively high efficiency of 7.36% was shown by the DSC prepared with electrolyte containing 75 wt% KI and 25 wt% Hex₄NI. This study reveals that the salt combination of KI and Hex₄NI, which has not been reported before, is a suitable binary iodide salt mixture to prepare highly efficient DSCs. The replacement of tetra-hexylammonium ions by K⁺ ions improves the charge transport in the electrolyte; however, the best solar cell performance is shown by the mixed salt system with 75 wt% KI and 25 wt% Hex₄NI, which is not the highest conductivity composition. Therefore, the exhibited high efficiency of 7.36% is evidently due to the binary cation effect.

High-Performance and Hysteresis-Free Perovskite Solar Cells Based on Rare-Earth-Doped SnO2 Mesoporous Scaffold

Tin oxide (SnO₂), as electron transport material to substitute titanium oxide (TiO₂) in perovskite solar cells (PSCs), has aroused wide interests. However, the performance of the PSCs based on SnO₂ is still hard to compete with the TiO₂-based devices. Herein, a novel strategy is designed to enhance the photovoltaic performance and long-term stability of PSCs by integrating rare-earth ions Ln³⁺ (Sc³⁺, Y³⁺, La³⁺) with SnO₂ nanospheres as mesoporous scaffold. The doping of Ln promotes the formation of dense and large-sized perovskite crystals, which facilitate interfacial contact of electron transport layer/perovskite layer and improve charge transport dynamics. Ln dopant optimizes the energy level of perovskite layer, reduces the charge transport resistance, and mitigates the trap state density. As a result, the optimized mesoporous PSC achieves a champion power conversion efficiency (PCE) of 20.63% without hysteresis, while the undoped PSC obtains an efficiency of 19.01%. The investigation demonstrates that the rare-earth doping is low-cost and effective method to improve the photovoltaic performance of SnO₂-based PSCs.

A study of the nanostructure and efficiency of solid-state dye-sensitized solar cells based on a conducting polymer

In this work the nanostructure and efficiency of solid-state dye-sensitized solar cells based on a conducting polymer have been investigated. A conducting polymer has been used as a solid-state electrolyte in the dye-sensitized solar cells. The polymer used in this study is a form of polythiophene synthesized in aqueous media. The obtained polymers were in two different structures: nanoparticles and networks. The structure of the synthesized polymers has been investigated using transmission electron microscope (TEM) and atomic force microscope (AFM). Furthermore, the optical and electrical properties of the synthesized polymers have also been considered. Solid-state dye-sensitized solar cells (SSDSCs) have been successfully constructed using these two polymers in addition to the linear poly(3-hexylthiophene) (P3HT). The photovoltaic characteristics of the assembled solar cells showed a good performance under annealing at 100 °C when using the network structure of polythiophene with a conversion power efficiency of 0.83%, while the nanoparticles polythiophene achieved 0.15% efficiency compared to 5.6 × 10⁻⁵% when using P3HT.

Pairing of Luminescent Switch with Electrochromism for Quasi-Solid-State Dual-Function Smart Windows

Smart window is a promising green technology with feature of tunable transparency under external stimuli to manage light transmission and solar energy. However, more functions based on the intelligent management of the solar spectrum need to be integrated into present smart windows. In this work, a dual-function smart window is fabricated by pairing the luminescent switch with the electrochromic window. The dual function is based on a single fluorine doped tin oxide coated glass functionalized with tungsten oxide and copper nanocluster, among which tungsten oxide serves as an electrochromic material and copper nanocluster provides photoinduced luminescence. Along with the regulation of the visible light based on the electrochromism of the window, the luminescence can be finely switched on and off, which establishes a pair of reversible states ("on" and "off") for the dual-function smart window. The contrast between two states reaches 88%. Furthermore, the manipulation of dual-function smart window is highly reversible with a short response time of 12.6 s. This prototype of dual-function smart window paves the way for developing multifunctional smart windows by integrating different functional materials into one smart window based on the rational management of the solar spectrum.

Pyridinium-clubbed dicationic ionic liquid electrolytes for efficient next-generation photo harvesting

A new series of pyridinium based dicationic ionic liquids was designed and synthesized. The synthesized ionic liquids have excellent thermal stability and good ionic conductivity. They can be used as electrolytes in photovoltaic devices.

In Situ Gelation of Poly(vinylidene fluoride) Nanospheres for Dye-Sensitized Solar Cells: The Analysis on the Efficiency Enhancement upon Gelation

The in situ gelation that utilizes the dissolution of polymers inside the cell is allowed high concentration polymer gel without concerns regarding high viscous electrolyte incorporation into the cell as in the conventional approach. We demonstrate the in situ gelation of polymer composite electrolytes using poly(vinylidene fluoride) nanospheres (PVdF NSs). The PVdF NSs were synthesized by high pressure emulsion polymerization using gaseous vinylidene fluoride monomers. Compared to the liquid electrolyte (LE) DSCs without PVdF gelation, the PVdF polymer gel electrolyte (PGE) DSCs displayed higher η than the LE DSCs; specifically, the 10 wt % PVdF PGE DSCs display 8.1% of the η, while the LE DSCs only display 6.5%. We characterized the effect of PVdF PGE on the photovoltaic parameters in detail. We also compared the long-term stability of DSCs containing LE and PVdF PGE. The DSCs with PVdF PGE exhibited high stability compared to the LE DSCs, similar to a conventional PGE system. We believe that this facile in situ gelation approach could be utilized for not only the practical application of polymer gel electrolytes DSCs but also for various energy-storage devices.

Direct light-induced polymerization of cobalt-based redox shuttles: an ultrafast way towards stable dye-sensitized solar cells

The photopolymerization of Co(II)/Co(III) complexes for dye-sensitized solar cells (DSSCs) by means of a fast, inexpensive, in situ and inhibition-free process has been examined. We have succeeded in fabricating high-performance DSSCs able to retain a light-to-electricity power conversion efficiency exceeding 6.5% (8.5% at low intensity) after 1800 h of mixed (light on/off, temperature high/low) accelerated aging tests, thus revealing a possible way for the stabilization of these record-holding redox pairs.

Fabrication of TiO2@ZnAl-layered double hydroxide based anode material for dye-sensitized solar cell

A TiO₂@ZnAl-layered double hydroxide nanocomposite was prepared by the co-precipitation method; then, the product was calcined in order to obtain the TiO₂@MMO nanocomposite, and use as anode material in dye-sensitized solar cell (DSSC).

Improving energy relay dyes for dye-sensitized solar cells by use of a group of uniform materials based on organic salts (GUMBOS)

Energy relay dyes based on GUMBOS displayed improved characteristics in comparison to respective parent dyes including solubility and solar efficiency.