Impact of copper and cobalt-based metal-organic framework materials on the performance and stability of hole-transfer layer (HTL)-free perovskite solar cells and carbon-based.

This article investigates the impact of metal-organic frameworks (MOFs) on the performance and stability of perovskite solar cells (PSCs), specifically focusing on the type of metal and the morphology of the MOF. Two types of MOFs, copper-benzene-1,3,5-tricarboxylate (Cu-BTC MOF) with spherical morphology and cobalt-benzene-1,3,5-tricarboxylate (Co-BTC MOF) with rod morphology, are synthesized and spin-coated on TiO2 substrates to form FTO/TiO2/MOF/CH3NH3PbI3/C-paste PSCs. The morphology and size of the MOFs are characterized by scanning electron microscopy (SEM), and the crystallinity and residual PbI2 of the perovskite films are analyzed by X-ray diffraction (XRD). The results show that the Co-BTC MOF PSC exhibits the highest power conversion efficiency (PCE) of 10.4% and the best stability, retaining 82% of its initial PCE after 264 h of storage in ambient air. The improved performance and stability are attributed to the enhanced crystallinity and reduced residual PbI2 of the perovskite film after Co-BTC MOF modification. The paper showcases the immense potential of MOF-based interlayers to revolutionize PSC technology, offering a path toward next-generation solar cells with enhanced performance and longevity.

Effect of dye complex structure on performance in DSSCs; An experimental and theoretical study.

Use of cobalt-complexes as dye in dye sensitized solar cells (DSSCs) has been a viable contender in the field of photovoltaics due to their low cost, easy production, and wide availability of sources. In this study, we investigated the effect of succinic acid (suc), 1,10-phenanthroline (phen), and benzene-1,3,5-tricarboxylate (BTC) as ligand in metals complex sensitizers with these general formulas: (1) [Co(suc)]n, (2) [Co2(suc)2(phen)2], (3) [Co3(BTC)2(H2O)n]n, and (4) [Co(HBTC) (phen) (H2O)2]; for DSSCs. The bandgap, and energy levels have an important role in photoelectron emission during photovoltaic processes. The bandgap, and energy levels of these dyes (1-4) were estimated by Ultraviolet-Visible (UV-Vis), spectroscopies, and cyclic voltammetry (CV). Delocalized π-electron of phenanthroline in two compounds (2, 4) by effectively reducing band gap energies leads to power conversion efficiency (PCE) of 0.511%, and 1.006%, respectively. Their PCEs to compounds (1, 3) showed an approximate increase of 60%, and 31%, respectively. Furthermore, BTC ligands by more coordinated carboxylate groups in contrast with succinic molecules due to binding sites with TiO2 cause further enhancement in the efficiency for compounds (3, 4) in contrast with compounds (1, 2). Reasonable agreement is found between experimental and theoretical values calculated using density functional theory (DFT) for the bandgaps and energy levels.

Impact of climate change on ecological quality indicators and biogeochemical fluxes in the Baltic sea: a multi-model ensemble study.

Multi-model ensemble simulations using three coupled physical-biogeochemical models were performed to calculate the combined impact of projected future climate change and plausible nutrient load changes on biogeochemical cycles in the Baltic Sea. Climate projections for 1961-2099 were combined with four nutrient load scenarios ranging from a pessimistic business-as-usual to a more optimistic case following the Helsinki Commission's (HELCOM) Baltic Sea Action Plan (BSAP). The model results suggest that in a future climate, water quality, characterized by ecological quality indicators like winter nutrient, summer bottom oxygen, and annual mean phytoplankton concentrations as well as annual mean Secchi depth (water transparency), will be deteriorated compared to present conditions. In case of nutrient load reductions required by the BSAP, water quality is only slightly improved. Based on the analysis of biogeochemical fluxes, we find that in warmer and more anoxic waters, internal feedbacks could be reinforced. Increased phosphorus fluxes out of the sediments, reduced denitrification efficiency and increased nitrogen fixation may partly counteract nutrient load abatement strategies.

Sonochemical synthesis of a novel nano-rod two-dimensional zinc(II) coordination polymer; preparation of zinc(II) oxide nanoparticles by direct thermolyses.

A novel mixed-ligand zinc(II) coordination polymer, {[Zn(µ-4,4'-bipy)(µ-3-bpdh)(H(2)O)(2)](ClO(4))(2)·(4,4'-bipy)(0.5)}(n) (1); 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene and 4,4'-bipy=4,4'-bipyridine, has been synthesized and characterized by IR, (1)HNMR and (13)CNMR spectroscopy. The single crystal X-ray data of compound 1 shows that this coordination polymer grows in two dimensions by two different bridging ligands, 4,4'-bipy and 3-bpdh. Also, nano-scale of compound 1 has been synthesized by sonochemical method and characterized by IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Thermal stability of compound 1 in single crystalline and nano-scale form was carried out by thermal gravimetric (TG) and differential thermal analysis (DTA). The ZnO nanoparticles were obtained by calcination of compound 1 at 500°C under air atmosphere and by thermolyses in oleic acid at 200°C. The zinc(II) oxide nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).