We report a comprehensive spectroscopic, microscopic, and device-level investigation of the ambient-driven degradation of PTQ10:IDIC bulk-heterojunction organic solar cells (BHJ-OSCs), up to 500 h. The power conversion efficiency dropped from 9.51% to 7.69% (≈19% relative loss), primarily due to a decrease in short-circuit current density (JSC 15.93 to 13.82 mA cm-2), while the open-circuit voltage remained largely stable (0.92 to 0.90 V). Atomic force microscopy reveals surface smoothing upon ageing, with the root-mean-square roughness decreasing from 4.29 to 3.45 nm, and the UV-vis absorption spectra show negligible changes, indicating preserved bulk light-harvesting capability. In contrast, X-ray photoelectron spectroscopy indicates pronounced surface compositional evolution, with a decrease in oxygen (5.18 to 3.18%) and a substantial increase in fluorine content (3.23 to 7.23%), consistent with fluorine-rich surface segregation or reorientation. Ultraviolet photoelectron spectroscopy further reveals a 0.48 eV reduction in surface work function, indicative of surface dipole modification and near-surface electronic reorganization. Collectively, these results demonstrate that ambient ageing primarily impacts interfacial chemistry and morphology rather than bulk optoelectronic properties, highlighting interfacial engineering and encapsulation as effective strategies for improving long-term device stability.

Electrochemical etching is a scalable route to engineer nanoporous architectures in doped GaN, but cross-comparative investigations spanning the full electrolyte chemical window are still very limited. Here, we explore the electrochemical etching of Si-doped n-GaN in acidic, alkaline, and neutral electrolytes and correlate morphology, optical properties, and surface chemistry by using various characterization and simulation methodologies. Our findings reveal that the electrolyte with different pH values not only affects the pore size and density but also alters the dominant etching mode, which leads to morphologies ranging from interconnected "sponge-like" three-dimensional pore networks to intact surfaces with slightly and anisotropically etched pores beneath. We have established semiquantitative models to elaborate the changes in near-band edge absorption due to disorders of the pores and to describe the surface oxidation/hydroxylation, through respective optical and x-ray photoelectron spectroscopy measurements. The models are further corroborated with the Raman observations, supporting a unified picture in which porosification increases disorder/local strain fluctuations. We envisage that this work offers important information on the electrochemical etching of III-nitrides using electrolytes in full pH ranges and proposes new analytical methods, which are valuable in developing power-efficient GaN optoelectronic devices.

ABSTRACT Perovskite solar cells have achieved high efficiencies but remain limited by instabilities. For the opaque metal rear electrode, Au is commonly used to achieve stable operation but is impractical for scalable photovoltaics due to cost. We investigate the effect of a 5 nm chromium (Cr) interlayer beneath low‐cost metals (Al, Ag, Cu) to inhibit metal interdiffusion. Cr/Al electrodes yield devices with high efficiencies (up to 24.7%) and operational stability comparable to reference devices using Au rear electrodes under heat and light stress, with raw material costs reduced by five orders of magnitude. At the front semi‐transparent electrode, through which sunlight will be incident, we identify indium diffusion from indium tin oxide (ITO) as a key degradation mechanism, revealed via depth‐resolved mass spectrometry. We demonstrate that replacing ITO with fluorine‐doped tin oxide (FTO) substantially improves stability. Combining both improvements, FTO with Cr/Al contacts, produces devices retaining >66% of the initial efficiency after >1000 h ageing at 75 °C under simulated sunlight. These results highlight the critical role of electrode selection on perovskite solar cell durability and provide a practical route toward stable and cost‐effective perovskite photovoltaics.

Roll-to-Roll (R2R) deposition offers a promising route for scaling up the production of perovskite solar cells (PSCs); however, the performance of R2R-fabricated devices still lags behind those produced through laboratory-scale methods. One significant factor contributing to this performance gap, particularly in P-I-N structured devices, is the use of suboptimal hole transport layers (HTLs), such as poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS). In this study, we explore the potential of replacing PEDOT:PSS with poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), a more efficient and stable HTL. While undoped PTAA alone shows promise, its application on the rough surface of PET-ITO substrates is insufficient to fully replace PEDOT:PSS, leading to reduced device performance. However, when combined with a PEDOT:PSS buffer layer, PTAA demonstrated significant improvements, achieving a power conversion efficiency (PCE) of 15.2% compared to 12.6% with PTAA alone using R2R deposition. To better understand the coating characteristics and interactions of these materials, we conducted a detailed analysis of the surface topography of PET-ITO and the HTL layer using X-ray photoelectron spectroscopy (XPS) mapping. This study provides critical insights into the synergistic effects of PEDOT:PSS and PTAA, highlighting their combined potential for enhancing the efficiency of R2R-fabricated PSCs.

Ambient particulate matter (PM) represents a significant global environmental and public health concern. Exposure to elevated levels of PM, particularly nanoparticles, is associated with serious health risks. Nanoparticles (PM0.1) originate from a variety of sources, including vehicular emissions, biomass combustion, and human activities. Therefore, this study examines PM0.1 and PM0.5–1.0 levels in Pathumtani, Thailand. The average concentrations of PM0.1 collected under wet and dry conditions were 13.47 µg/m³ and 18.48 µg/m³, respectively, while those of PM0.5–1.0 were 18.34 µg/m³ and 26.47 µg/m³. Various characterization techniques were employed, including X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX). XPS was utilized to identify elemental and chemical compositions, while TEM and SEM were used to analyze morphology and quantify size distributions. The nanoparticles contained the following elements: carbon (26

Production of silicon solar cells necessitates cleanrooms to prevent dust contamination, which can lead to defects and reduced performance. This poses challenges for scaling up manufacturing and improving accessibility for device manufacture in less developed economies as cleanrooms represent an expensive and energy intensive investment, and so it is key that the next generation of solar technology differentiates from this. Perovskite has the potential to be far more robust and resilient to defects caused by dust particles, which then impacts on the capital cost of the equipment required for manufacture. This study evaluates the effects of non-conductive dust on planar perovskite devices, testing two different device structures with efficiencies exceeding 16%, testing an active area of 0.09 cm2. The setup simulated dust settling during the manufacturing process, expecting compromised performance in contaminated devices. Results revealed that devices with dust performed similarly to clean ones, with only limited losses in some performance metrics. High tolerance to contamination suggests that perovskite technology may remain operational under less controlled environments. These findings point toward a more accessible fabrication route reducing dependence on expensive cleanroom conditions typically required for silicon-based technologies.

Perovskite solar cells (PSCs) have burst into photovoltaic (PV) research, revolutionising it and demonstrating that they can achieve performances comparable to technologies already on the market. Despite that, the major limitation of PSCs' commercialisation is their poor environmental stability. Inorganic carriers transporting materials have gained attention for enhancing PSCs' durability due to their superior stability and non-hygroscopic nature. Among them, kesterite Cu2ZnSnS4 (CZTS) is a promising inorganic hole transporting material (HTM) thanks to its optimal electronic properties, non-toxic, abundant elements, and simple solution deposition methods. Herein, the effect on the stability of inverted PSCs employing CZTS nanoparticles (NPs) as HTM is investigated by X-ray photoelectron and ultraviolet photoelectron spectroscopy, together with steady-state and time-resolved photoluminescence spectroscopies. Special attention was given to the alteration in the PV performances over time of the CZTS-based device compared to a control device with a common organic HTM. The enhanced stability of the CZTS NPs-based devices in opposition to degradation of the devices with a [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) self-assembled monolayer as HTM was demonstrated through solar simulator measurements and external quantum efficiency. The efficiency of a CZTS-based p-i-n PSC increased by 34% after three weeks, while the efficiency of the organic HTM-based device decreased by 16% during the same period. Furthermore, CZTS-based PSCs showed a drop-in efficiency of 80% after four days under a humidity test at 70% RH, while the efficiency of the organic HTM-based devices dropped by 80% after two days under the same conditions. Moreover, analysis of the photoluminescence spectra reveals no modification of the CZTS-based PSCs.

This study investigates the impact of power density on the surface properties of ethylene tetrafluoroethylene (ETFE) films treated with atmospheric pressure nitrogen plasma. Increasing power density consistently enhances the wettability of treated substrates. ATR-FTIR and XPS analyses reveal the formation of C=C bonds, C=CF 2 stretching vibrations, defluorination, and the introduction of oxygenated and nitrogenated functionalities. T-peel tests with acrylic adhesive tape show substantial increases in peel strength post-treatment, with higher power densities yielding more uniform modifications. Reducing polymer line speed further enhances peel strength. Long-term aging tests indicate minimal peel strength reduction after 340 days. The study emphasizes controlling plasma treatment parameters to optimize ETFE film bonding properties, benefiting diverse applications.

Biomaterial surface engineering and the integration of cell-adhesive ligands are crucial in biological research and biotechnological applications. The interplay between cells and their microenvironment, influenced by chemical and physical cues, impacts cellular behavior. Surface modification of biomaterials profoundly affects cellular responses, especially at the cell-surface interface. This work focuses on enhancing cellular activities through material manipulation, emphasizing silanization for further functionalization with bioactive molecules such as RGD peptides to improve cell adhesion. The grafting of three distinct silanes onto silicon wafers using both spin coating and immersion methods was investigated. This study sheds light on the effects of different alkyl chain lengths and protecting groups on cellular behavior, providing valuable insights into optimizing silane-based self-assembled monolayers (SAMs) before peptide or protein grafting for the first time. Specifically, it challenges the common use of APTES molecules in this context. These findings advance our understanding of surface modification strategies, paving the way for tailoring biomaterial surfaces to modulate the cellular behavior for diverse biotechnological applications.

Sodium-ion batteries represent a sustainable and cost-effective solution for grid-scale energy storage. However, the reliance on cathode materials containing scarce transition metals currently limits their wider adoption. Carbonaceous materials present an environmentally sustainable and economically viable alternative. This study investigates the application of reduced graphene oxide as a cathode active material. A detailed analysis of the storage mechanism and its dependence on the morphological and chemical structure revealed that it combines surface capacitance and faradaic reactions. The key factors responsible for high capacity and long cycle life are the open structure of graphene sheets and the presence of functional oxygen and nitrogen groups where Na+ ions are stored in the R-C 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 O + Na+ + e- <-> R-C-O-Na reaction. A good understanding of the mechanism allowed optimisation of cycling conditions in a proof-of-concept all-carbon full cell incorporating reduced graphene oxide and hard carbon as a cathode and an anode, respectively. The system displays good energy density (80 W h kg-1) and remarkable stability over 500 cycles. The gained insights will support the rational design of more efficient carbonaceous electrodes. This work investigates the energy storage mechanism responsible for high capacity and stability of reduced graphene oxide cathodes for sodium-ion batteries.

The heterostructure WO3/BiVO4-based photoanodes have garnered significant interest for photoelectrochemical (PEC) solar-driven water splitting to produce hydrogen. However, challenges such as inadequate charge separation and photocorrosion significantly hinder their performance, limiting overall solar-to-hydrogen conversion efficiency. The incorporation of cocatalysts has shown promise in improving charge separation at the photoanode, yet mitigating photocorrosion remains a formidable challenge. Amorphous metal oxide-based passivation layers offer a potential solution to safeguard semiconductor catalysts. We examine the structural, surface morphological, and optical properties of two-step-integrated sputter and spray-coated TiO2 thin films and their integration onto WO3/BiVO4, both with and without NiOOH cocatalyst deposition. The J-V experiments reveal that the NiOOH cocatalyst enhances the photocurrent density of the WO3/BiVO4 photoanode in water splitting reactions from 2.81 to 3.87 mA/cm2. However, during prolonged operation, the photocurrent density degrades by 52%. In contrast, integrated sputter and spray-coated TiO2 passivation layer-coated WO3/BiVO4/NiOOH samples demonstrate a ∼88% enhancement in photocurrent density (5.3 mA/cm2) with minimal degradation, emphasizing the importance of a strategic coating protocol to sustain photocurrent generation. We further explore the feasibility of using natural mine wastewater as an electrolyte feedstock in PEC generation. Two-compartment PEC cells, utilizing both fresh water and metal mine wastewater feedstocks exhibit 66.6 and 74.2 μmol/h cm2 hydrogen generation, respectively. Intriguingly, the recovery of zinc (Zn2+) heavy metals on the cathode surface in the mine wastewater electrolyte is confirmed through surface morphology and elemental analysis. This work underscores the significance of passivation layer and cocatalyst coating methodologies in a sequential order to enhance charge separation and protect the photoanode from photocorrosion, contributing to sustainable hydrogen generation. Additionally, it suggests the potential of utilizing wastewater in electrolyzers as an alternative to freshwater resources.

Carbon dioxide electroreduction (CO2ER) coupled with water oxidation (oxygen evolution reaction, OER) presents a promising solution for effectively mitigating global warming. However, this process is compromised by the sluggish OER, which yields only undesirable O-2. Here, we couple selective CO2ER with partial ethylene glycol oxidation (EGO) to concurrently produce formate in both half-reactions. The enhancement of active sites and optimization of formate selectivity are the principal objectives during the design of both electrodes. For CO2ER, redox stabilization of Sn-based cathodes is investigated via Pb doping, thus ultimately improving the Faradaic efficiency from 68% to similar to 89%. To replace OER with EGO, we employed CuO@Ni(OH)(2) on copper foam, reducing the applied potential by 200 mV at 50 mA/cm(2). Finally, an EGO-coupled CO2 electrolyzer achieves 10 mA/cm(2) at an overall cell voltage 180 mV lower than that of a conventional CO2 electrolyzer. This study showcases the integration of divergent electrochemical processes for concurrent electrosynthesis without precious metals to achieve cost-effective and sustainable formate production from CO2 and plastic waste.

Sunflower oil was used as a templating agent for the development of sustainable, novel porous, titanosilicate microspheres. They are highly effective in removal of organic pollutants from water via adsorption and photocatalysis, and have potential applications in advanced tertiary water-treatment.

The heterostructure WO3/BiVO4-based photoanodes have garnered significant interest for photoelectrochemical (PEC) solar-driven water splitting to produce hydrogen. However, challenges such as inadequate charge separation and photocorrosion significantly hinder their performance, limiting overall solar-to-hydrogen conversion efficiency. The incorporation of cocatalysts has shown promise in improving charge separation at the photoanode, yet mitigating photocorrosion remains a formidable challenge. Amorphous metal oxide-based passivation layers offer a potential solution to safeguard semiconductor catalysts. We examine the structural, surface morphological, and optical properties of two-step-integrated sputter and spray-coated TiO2 thin films and their integration onto WO3/BiVO4, both with and without NiOOH cocatalyst deposition. The J-V experiments reveal that the NiOOH cocatalyst enhances the photocurrent density of the WO3/BiVO4 photoanode in water splitting reactions from 2.81 to 3.87 mA/cm(2). However, during prolonged operation, the photocurrent density degrades by 52%. In contrast, integrated sputter and spray-coated TiO2 passivation layer-coated WO3/BiVO4/NiOOH samples demonstrate a similar to 88% enhancement in photocurrent density (5.3 mA/cm(2)) with minimal degradation, emphasizing the importance of a strategic coating protocol to sustain photocurrent generation. We further explore the feasibility of using natural mine wastewater as an electrolyte feedstock in PEC generation. Two-compartment PEC cells, utilizing both fresh water and metal mine wastewater feedstocks exhibit 66.6 and 74.2 mu mol/h cm(2) hydrogen generation, respectively. Intriguingly, the recovery of zinc (Zn2+) heavy metals on the cathode surface in the mine wastewater electrolyte is confirmed through surface morphology and elemental analysis. This work underscores the significance of passivation layer and cocatalyst coating methodologies in a sequential order to enhance charge separation and protect the photoanode from photocorrosion, contributing to sustainable hydrogen generation. Additionally, it suggests the potential of utilizing wastewater in electrolyzers as an alternative to freshwater resources.

Microscopy, electrochemical techniques and mechanical testing are used to investigate the effect of varying antimony additions (0.45–1.8 wt%) on the microstructure and corrosion properties of zinc-magnesium-aluminium coating alloys. Samples were produced by splat casting to produce high cooling rates similar to those seen in a continuous galvanising line. X-Ray Microscopy reveals that the Sb additions produce disk-shaped Mg3Sb2 intermetallics, subsequently reducing or eliminating the MgZn2 eutectic. Electrochemical testing in 1 wt% NaCl shows that the Mg3Sb2 phase is cathodic with respect to the bulk alloy with slower oxygen reduction kinetics. The decrease in eutectic content leads to less intense anodic activity. The combined effect is anodic and cathodic deactivation, which leads to a 43% reduction in corrosion rate as measured through LPR compared to the base alloy. This work shows that quaternary additions to ZMA coating alloys can be a potential route to improved corrosion resistance for galvanic protection.

Metal oxide charge transport materials are preferable for realizing long-term stable and potentially low-cost perovskite solar cells(PSCs).However,due to some technical difficulties(e.g.,intricate fabrication protocols,high-temperature heating process,incompatible solvents,etc.),it is still challenging to achieve efficient and reliable all-metal-oxide-based devices.Here,we developed efficient inverted PSCs(IPSCs)based on solution-processed nickel oxide(NiOx)and tin oxide(SnO2)nanoparticles,working as hole and electron transport materials respectively,enabling a fast and balanced charge transfer for photogenerated charge carriers.Through further understanding and optimizing the perovskite/metal oxide interfaces,we have realized an outstanding power conversion efficiency(PCE)of 23.5％(the bandgap of the perovskite is 1.62 eV),which is the highest efficiency among IPSCs based on all-metal-oxide charge transport materials.Thanks to these stable metal oxides and improved interface properties,ambient stability(retaining 95％of initial PCE after 1 month),thermal stability(retaining 80％of initial PCE after 2 weeks)and light stability(retaining 90％of initial PCE after 1000 hours aging)of resultant devices are enhanced significantly.In addition,owing to the low-temperature fabrication procedures of the entire device,we have obtained a PCE of over 21％for flexible IPSCs with enhanced operational stability.