Introduction of cadmium chloride additive to improve the performance and stability of perovskite solar cells

Structural characteristics of Saccharomyces cerevisiae mannoprotein and its immunomodulatory activities on RAW264.7 cells

An enzyme-extracted mannoprotein (SC-MP) from the cell wall of Saccharomyces cerevisiae was investigated for structural characteristics and immunomodulatory effects on RAW264.7. The SC-MP was purified using the diethylaminoethyl (DEAE) cellulose column and gel column to isolate 2 fractions (MP-1 and MP-2), with MP-1 as the dominant fraction (yield, 87.4 %). The results of composition analyses showed that MP-1, which comprises 88.13 % (w/w) sugar and 6.93 % (w/w) protein, had lower protein content than SC-MP (20.89 %, w/w). Monosaccharide analysis showed MP-1 comprises mannose, glucose, and glucosamine in a molar ratio of 97.64:1.46:0.38. The molecule weight of MP-1 was 141 kDa. The MP-1 was further analyzed using GC-MS, NMR to elucidate its structural characteristics, the results showed that the main sugar residue types of MP-1 included T-D-Manp (45.41 mol%), 1,2,6-D-Manp (21.58 mol%), 1,2-D-Manp (19.45 mol%), and 1,6-D-Manp (6.06 mol%), 1,3-D-Manp (3.91 mol%), and a little amount of 1,6-D-Glcp (3.59 mol%). The mannoses polymerized to form mannan and mano-oligosaccharide. Mannan, which has α-1,6-mannan backbone branched with α-1,2-mannan and α-1,3-mannan, connected to protein by N-glycosylation (via asparagine), and mano-oligosaccharide connected to protein by O-glycosylation (via serine or threonine). At 150 μg/mL concentrations, SC-MP and MP-1, which were different in purity, significantly stimulated the secretion of TNF-α and inhibited the secretion of IL-10 of RAW 264.7 cells, and MP-1 showed stronger effects. This study provided a scientific basis for further exploring the applications of yeast mannoprotein.

Cl alloying improves thermal stability and increases luminescence in iodine-rich inorganic perovskites

The inorganic perovskite CsPbI3 shows promising photophysical properties for a range of potential optoelectronic applications but is metastable at room temperature. To address this, Br can be alloyed into the X-site to create compositions such as CsPbI2Br that are stable at room temperature but have bandgaps >1.9 eV - severely limiting solar applications. Herein, in an effort to achieve phase stable films with bandgaps <1.85 eV, we investigate alloying chlorine into iodine-rich triple-halide CsPb(I0.8Br0.2-x Cl x )3 with 0 < x < 0.1. We show that partial substitution of iodine with bromine and chlorine provides a path to maintain broadband terrestrial absorption while improving upon the perovskite phase stability due to chlorine's smaller size and larger ionization potential than bromine. At moderate Cl loading up to ≈5%, X-ray diffraction reveals an increasingly smaller orthorhombic unit cell, suggesting chlorine incorporation into the lattice. Most notably, this Cl incorporation is accompanied by a significant enhancement over Cl-free controls in the duration of black-phase stability of up to 7× at elevated temperatures. Additionally, we observe up to 5× increased steady state photoluminescence intensity (PL), along with a small blue-shift. In contrast, at high loading (≈10%), Cl accumulates in a second phase that is visible at grain boundaries via synchrotron fluorescence microscopy and negatively impacts the perovskite phase stability. Thus, replacing small fractions of bromine for chlorine in the iodine-rich inorganic perovskite lattice results in distinct improvement thermal stability and optoelectronic quality while minimally impacting the bandgap.

Fabrication and Enhanced Performance Evaluation of TiO2@Zn/Al-LDH for DSSC Application: The Influence of Post-Processing Temperature

A sequence of dye-sensitized solar cells is proposed, utilizing TiO2@Zn/Al-layered double hydroxide (LDH) as their starting materials, in which Ruthenizer N719 was used as a photon absorber. The anticipated system was turned into sheet-like TiO2@mixed metal oxide (MMO) via post-processing treatment. The crystal quality indicated a relation to power conversion efficiency (PCE); this was combined with a comparable morphology profile. In detail, the optimum DSSC device exhibited average sheet-like thickness and a dye loading amount of 43.11 nm and 4.28 ×10-3 mM/cm-2, respectively. Concurrently, a considerable PCE enhancement of the optimum DSSC device (TiO2@MMO-550°) was attained compared to pristine MMO (0.91%), which could be due to boosted electron transfer efficiency. Of the fabricated devices, DSSC fabricated at 550° exhibited the highest PCE (1.91%), with a 35.6% enhancement compared to that obtained at 450°, as a result of its increased open-circuit voltage (3.29 mA/cm2) and short-circuit current (0.81 V). The proposed work delivers an enhanced efficiency as compared to similar geometries.

Advances in chloride additives for high-efficiency perovskite solar cells: multiple points of view

Chloride (Cl) additives are rather effective in improving the performance of perovskite solar cells (PSCs) through the modulation of crystallization process and surface morphology. After incorporating Cl-containing additives, the optoelectrical properties of perovskite films, such as the electron/hole diffusion length and carrier lifetime, are greatly enhanced. However, only a trace amount of Cl has been identified in the resultant perovskite film, and the mechanism of efficiency improvement induced by Cl remains unclear. In this review, we discuss organic and inorganic Cl additives systematically from the perspective of their solubility, volatility, cation size and chemical groups. In addition, the roles of residual Cl anions and cations are analyzed in detail. Finally, some valuable future perspectives of Cl additives are proposed.

Ternary Metal (Cu-Ni-Zn) Oxide Nanocomposite via an Environmentally Friendly Route

In this work, we report the engineering of sub-30 nm nanocomposites of CuO/ZnO/NiO by using Dodonaea viscosa leaf extract. Zinc sulfate, nickel chloride, and copper sulfate were used as salt precursors, and isopropyl alcohol and water were used as solvents. The growth of nanocomposites was investigated by varying the concentrations of precursors and surfactants at pH 12. The as-prepared composites were characterized by XRD analysis and found to have CuO (monoclinic), ZnO (hexagonal primitive), and NiO (cubic) phases with an average size of 29 nm. FTIR analysis was performed to investigate the mode of fundamental bonding vibrations of the as-prepared nanocomposites. The vibrations of the prepared CuO/ZnO/NiO nanocomposite were detected at 760 and 628 cm^-1, respectively. The optical bandgap energy of the CuO/NiO/ZnO nanocomposite was 3.08 eV. Ultraviolet-visible spectroscopy was performed to calculate the band gap by the Tauc approach. Antimicrobial and antioxidant activities of the synthesized CuO/NiO/ZnO nanocomposite were investigated. It was found that the antimicrobial activity of the synthesized nanocomposite increases with an increase in the concentration. The antioxidant activity of the synthesized nanocomposite was examined by using both ABTS and DPPH assays. The obtained results show an IC₅₀ value of 0.110 for the synthesized nanocomposite compared to DPPH and ABTS (0.512), which is smaller than that of ascorbic acid (IC₅₀ = 1.047). Such a low IC₅₀ value ensures that the antioxidant potential of the nanocomposite is higher than that of ascorbic acid, which in turn shows their excellent antioxidant activity against both DPPH and ABTS.

Development of Perovskite (MACl)0.33FA0.99MA0.01Pb(I0.99Br0.01)3 Solar Cells via n-Octylammonium Iodide Surface Passivation

The influence of n-octylammonium iodide (OAI, passive layer) on the types of phases formed in a (MACl)_0.33FA_0.99MA_0.01Pb(I_0.99Br_0.01)₃ perovskite film was studied using X-ray diffraction. Using UV spectrophotometric techniques, it was determined how varied OAI additive layer ratios affected the linear and nonlinear optical characteristics of glass substrates/FTO/compact TiO₂/mesoporous TiO₂/(MACl)_0.33FA_0.99MA_0.01Pb(I_0.99Br_0.01)₃ films. All films' direct optical bandgap energies were determined to be 1.54 eV. The effects of OAI addition on the films' photoluminescence intensity and emitted colors were also investigated. For the fabricated perovskite solar cells (PSCs) without an OAI passivation layer, the corresponding power conversion efficiency (PCE), open-circuit voltage (V_OC), short-circuit current density (J_SC), and fill factor (FF) values were 18.8%, 1.02 V, 24.6 mAcm^-2, and 75%, respectively. When the concentration of OAI reached 2 mg, the maximum obtained values of PCE, V_OC, J_SC, and FF were 20.2%, 1.06 V, 24.2 mAcm^-2, and 79%, respectively. The decreased trap density and increased recombination resistance were responsible for the improvement in solar cell performance.

Catalytic response and molecular simulation studies in the development of synthetic routes in trimeric triaryl pyridinium type ionic liquids

Under conventional and silica-supported Muffle furnace methods, water-soluble substituted trimeric triaryl pyridinium cations with various inorganic counter anions are synthesized. The solvent-free synthesis method is superior to the conventional method in terms of non-toxicity, quicker reaction times, ease of workup, and higher yields. Trimeric substituted pyridinium salts acted as excellent catalytic responses for the preparation of Gem-bisamide derivatives compared with available literature. To evaluate the molecular docking, benzyl/4-nitrobenzyl substituted triaryl pyridinium salt compounds with VEGFR-2 kinase were used with H-bonds, π-π stacking, salt bridges, and hydrophobic contacts. The results showed that the VEGFR-2 kinase protein had the most potent inhibitory activity. Intriguingly, the compound [NBTAPy]PF₆^- had a strongly binds to VEGFR-2 kinase and controlled its activity in cancer treatment and prevention.

Interfacial passivation of CsPbI3 quantum dots improves the performance of hole-transport-layer-free perovskite photodetectors

Photodetectors (PDs) suffer from dark current due to defects in the perovskite photosensitive layer. Contact between the photosensitive layer and carbon electrodes could result in recombination of carriers at the interface. In this work, CsPbI₃ quantum dots (QDs) were added between the photosensitive layer and the carbon electrode as the interfacial layer to passivate the surface defects of perovskite layer and improve the energy level matching at the interface. The effect of QDs concentrations on the passivation of the perovskite layer was investigated. It was found that the photoluminescence intensity of perovskite films was the strongest and the decay lifetime was the longest when the QDs concentration was 3 mg/mL. Owing to QDs passivation, the dark current of perovskite PD decreased by 94% from [Formula: see text] to [Formula: see text] A. The responsivity (R) at 605 nm improved by 27% from 0.29 to 0.37 A/W at 0 V bias voltage. The specific detectivity (D*) increased by 420% from [Formula: see text] to [Formula: see text] Jones.

Improving the potential of ethyl acetate green anti-solvent to fabricate efficient and stable perovskite solar cells

Until now, in all state-of-the-art efficient perovskite solar cells (PSCs), during the fabrication process of the perovskite layer, highly toxic anti-solvents such as toluene, chlorobenzene, and diethyl ether have been used. This is highly concerning and urgently needs to be considered by laboratories and institutes to protect the health of researchers and employees working towards safe PSC fabrication. Green anti-solvents are usually used along with low-performance PSCs. The current study solves the ineptitude of the typical ethyl acetate green anti-solvent by adding a potassium thiocyanate (KSCN) material to it. The KSCN additive causes delay in the perovskite growing process. It guarantees the formation of larger perovskite domains during fabrication. The enlarged perovskite domains reduce the bulk and surface trap density in the perovskite. It enables lower trap-facilitated charge recombination along with efficient charge extraction in PSCs. Overall, the developed method results in a champion performance of 17.12% for PSCs, higher than the 13.78% recorded for control PSCs. The enlarged perovskite domains warrant lower humidity interaction paths with the perovskite composition, indicating higher stability in PSCs.

Simulation and analysis of lead-free perovskite solar cells incorporating cerium oxide as electron transporting layer

The great demand for renewable energy has greatly contributed to the development of the solar cell industry. Recently, silicon solar cells have dominated the world market. The ease of processing gives perovskite solar cells (PSCs) an advantage over conventional silicon solar cells. Regular silicon photovoltaics require expensive, multi-step processes accomplished in a specialized ultraclean-chamber facility at an elevated temperature (>1000 °C) and highly vacuumed workspace. Hence, researchers and the solar cell industry have focused on PSC as a great rival to silicon solar cells. Despite this, the highest efficiency was obtained from lead-based PSC, which has a considerably high toxicity issue and low stability related to lead content, so the research field pays attention to lead-free perovskite solar cells. In this digital simulation, tin-based perovskite in this paper, methylammonium tin iodide (MASnI₃) with the use of cerium oxide (CeO_x) as an electron transporting layer (ETL) with varying percentages of oxygen, which means different shallow donor densities (ND). The optimum value for the thickness of the absorber layer (perovskite) was made, and the current–voltage characteristics and efficiency calculations were also accomplished for the best cell. Then an improvement was made by changing the ND value of CeO_x, and the best-optimized cell parameters were: open circuit voltage (V_OC) of 0.92 V, short circuit current density (J_SC) of 30.79 mA cm⁻², power conversion efficiency (PCE) of 17.77%, and fill factor (FF) of 62.86%.

In this digital simulation, tin-based with the use of CeO_x as an ETL with varying percentages of oxygen has been investigated.