The fabrication of narrow‐bandgap (NBG) Pb–Sn perovskites, with bandgaps typically around 1.1–1.3 eV, is often challenging due to issues related to repeatability, stability, and rapid crystallization kinetics. While Sn–Pb perovskites offer advantages such as defect tolerance and lower toxicity, they are also prone to inhomogeneous crystallization. Sn‐based component of perovskite crystallizes much faster than the Pb‐based component, leading to poor film coverage, pinholes, and rough morphologies. In this study, we employed gas quenching (GQ) instead of the commonly used antisolvent (AS) quenching to address the rapid crystallization issue. GQ approach resulted in slower crystallization and improved film quality. Besides, GQ produced more reproducible results compared to AS quenching. Devices fabricated using the GQ method also demonstrated better performance with higher open‐circuit voltage ( V OC ) values. Specifically, devices prepared with the AS method achieved a power conversion efficiency (PCE) of 18.3%, whereas those using the GQ method reached a PCE of 19.1%. This improvement in efficiency combined with enhanced reproducibility, the simplicity, and environmental friendliness of the GQ approach underscores its advantage for processing NBG Pb–Sn mixed perovskite films. Therefore, the GQ method holds significant potential for application in the fabrication of NBG Pb–Sn perovskite solar cells.

Hole‐selective self‐assembled monolayers (SAMs) based on carbazole head groups have enabled major performance improvements of perovskite solar cells (PSCs) by eliminating parasitic absorption and nonradiative losses. However, the energy levels of the carbazole‐based, commercially available SAMs poorly match the valence band maximum (VBM) of narrow‐bandgap, lead‐tin (Pb‐Sn) perovskites, relevant for tandem applications. In this work, we expand the library of SAMs compatible with Pb‐Sn PSCs by synthesizing four novel SAMs containing phenoxazine (POz) and phenothiazine (PTz) as their head groups and investigate their interaction with the Pb‐Sn perovskite in detail. We obtain working devices with all SAMs, but despite significant differences between the highest occupied molecular orbital (HOMO) levels of the SAMs, the open‐circuit voltage ( V OC ) and fill factor (FF) across devices remains similar, suggesting that the role of energy level alignment is less relevant at this interface. Through in‐depth analysis including photoluminescence quantum yield (PLQY), transient photocurrent (TPC), and combined time‐resolved surface photovoltage (trSPV) and time‐resolved photoluminescence (trPL) measurements, we unveil the charge extraction dynamics of these systems featuring different head groups and HOMOs. This work highlights that the SAMs’ structure affects the overall charge extraction process and provides insights into the strategies needed to maximize charge extraction for more efficient PSCs.

This study investigates the impact of the geometric fill factor (GFF) on the practical performance of organic solar cell (OSC) modules fabricated by two distinct approaches: a conventional hand‐made method and UV nanosecond laser patterning technique. Using the optimized PM6:L8‐BO photoactive system, two OSC modules—each comprising three sub‐cells—were fabricated under the same device dimensions (35 × 35 mm). Laser‐patterned module exhibited a substantial enhancement in GFF from 62.73% to 98.41%, resulting in an increase in the maximum output power ( P max ) from 69.67 mW to 124.25 mW. To evaluate the practical energy harvesting capability, capacitor‐charging experiments were performed under identical illumination conditions. The laser‐patterned module reached the target voltage of 2.5 V in 380 seconds, whereas the hand‐made module required 610 s to reach the same voltage. These results demonstrate that a cost‐effective UV nanosecond laser system can effectively optimize the GFF and nearly double the output power of OSC modules. Furthermore, comprehensive stability evaluations emphasize the importance of ensuring process reliability, highlighting the key technological challenges that must be addressed for future industrial implementation.

The exciton binding energy ( E b ) is recognized as a pivotal parameter governing charge separation in polymeric photocatalysts. Reducing E b in polymers enhances carrier generation, thereby boosting photocatalytic activity. Rationally constructing donor–acceptor (D–A) architectures in heptazine‐based polymers offers an effective strategy to overcome intrinsic excitonic limitations. In this work, CN x ( x = 0.015, 0.025, 0.05) materials with intramolecular D–A configurations were developed by integrating electron‐donating units with heptazine acceptor motifs. The optimized material CN 0.025 exhibits a 29% reduction in E b (97 → 69 meV) and extended visible‐light absorption, attributable to enhanced π‐conjugation and modulated electronic structures. Remarkably, under visible‐light irradiation, CN 0.025 achieves 97.7% degradation of 2,4‐dichlorophenol (10 ppm) within 50 min. Moreover, CN x exhibits a 29.8‐fold higher CO yield than pure g‐C 3 N 4 in photocatalytic CO 2 reduction. Electrochemical photocurrent measurements reveal a remarkable enhancement in the photocurrent response of CN 0.025 relative to g‐C 3 N 4 , which suggests more efficient exciton dissociation and increased carrier availability at the catalytic surface for subsequent redox reactions. This work establishes a paradigm for exciton dissociation in polymeric photocatalysts through engineered D–A nanoarchitectures.

The bandgap tunability of lead sulfide (PbS) quantum dots (QDs) positions them as a promising candidate for tandem solar cells (TSCs). However, the power conversion efficiency (PCE) of all‐PbS QDs TSCs is lagging much behind the theoretical efficiency limit due to the deficient carrier recombination capability of the interconnection layer (ICL). In this study, we fabricated all‐PbS QDs TSCs utilizing 1.40 and 0.95 eV PbS QDs for the top and bottom subcells, respectively. We developed two kinds of ICLs, 1,2‐ethanedithiol capped PbS QDs (PbS‐EDT)/Au/ZnO and PbS‐EDT/SAMs/Au/ZnO, where self‐assembled monolayers (SAMs) of 4‐(7H‐dibenzo[c,g]carbazol‐7‐yl)butylphosphonic acid (4PADCB) were the first time applied for all‐PbS QD TSCs. The SAMs bound with the PbS‐EDT hole transport layer (HTL), enhancing hole extraction from the top cell via their conjugated π‐system. Furthermore, they served to passivate traps at the HTL/Au interface, thereby reducing nonradiative recombination losses. Consequently, the top cell achieved 8.36% PCE with a semitransparent absorber layer. After the SAMs modification, it established a uniform and low‐potential surface, facilitating a uniform distribution of a thin Au recombination layer (RL). The newly developed RL enhanced hole–electron recombination. The resulting SAMs‐based TSCs achieved a certified PCE of 11.95%, more than 2% net PCE improvement over our last record data.

Nanostructured α‐hematite (Fe 2 O 3 ) is a widely studied material for photoanode applications, particularly for driving the oxygen evolution reaction (OER) under visible light irradiation in photoelectrochemical (PEC) cells. Our recent work has shown that Fe 2 O 3 suffers from photocorrosion in alkaline and neutral electrolytes, with a noticeable decline in performance after 5 h of operation. This highlights the need for strategies that enhance the stability of Fe 2 O 3 ‐based photoanodes. To enhance the stability of Fe 2 O 3 nanorods (NR), we employed atomic layer deposition (ALD) to coat the NR with a well‐defined, controlled TiO 2 overlayer designed to protect the photoanode from photocorrosion during PEC operation. The influence of overlayer thickness is evaluated regarding the PEC activity, stability, and photocurrent retention in alkaline electrolyte using a PEC scanning flow cell coupled to an inductively coupled plasma mass spectrometer (PEC‐ICP‐MS). This setup can quantify metal dissolution during PEC OER, allowing the characterization of the photo‐degradation under realistic illumination conditions. An accelerated stress test (AST) protocol was designed to drive degradation faster and obtain insightful information about the stability of the TiO 2 @Fe 2 O 3 heterostructures using in situ PEC‐ICP‐MS. PEC‐ICP‐MS measurements demonstrate that the TiO 2 coating significantly enhances the photocorrosion resistance of Fe 2 O 3 NR in alkaline electrolytes during operation. A TiO 2 thickness of 2.8 nm (50 ALD cycles) offered the most favorable compromise between activity, photocurrent retention, and decrease of Fe dissolution. The proposed methodology combines in situ stability quantification and ASTs as a powerful tool to advance material development and can be extended to other protected photoanodes.

Effective photovoltaic module recycling is essential for improving the sustainability of solar technologies and securing the silver supply chain. One method of recycling silver from end‐of‐life photovoltaic modules is electrodeposition following nitric acid leaching. This study investigates how nitric acid concentration affects the electrochemistry and recovery of silver in a controlled three‐electrode system. Silver recovery and Faradaic efficiency were found to increase with acid concentration from 0.1 м. Maximum values of 97% silver recovery and 96% Faradaic efficiency at 4.0 м nitric acid were observed using a silver working electrode at constant current deposition of −20 mA/cm 2 . Past this point, both recovery and efficiency were observed to decline sharply due to enhanced silver dissolution kinetics. It was also found at low nitric acid concentrations (<2.0 м) silver oxynitrate formed as a solid deposit at the counter electrode, while at higher concentrations (>2.0 м) silver (II) complexes formed but remained dissolved in the electrolyte. Industrially, a nitric acid concentration in the range of 2.0–4.0 м is recommended to optimize silver recovery and efficiency while minimizing anode fouling in a full cell arrangement.

The increasing use of plug and play photovoltaic systems has raised concerns about their safety, especially with nonprofessional installations, which existing standards only partially address. This study proposes a black box testing approach to assess the personal safety of plug and play inverters. A total of 25 microinverters are assessed using three tests: (1) analyzing the residual voltage at the mains plug after disconnection, (2) the feed‐in current increase under low grid voltage conditions, and (3) the maximum touch temperature during operation. Residual voltage testing reveals that 56% of the inverters comply with the limit of the latest official German plug and play system standard draft and behave similarly to other tested electrical devices. Further investigation is required to determine if exceeding this limit presents a direct safety risk. However, adding a relay was identified as an effective measure to ensure compliance. Under low voltage conditions, current increases up to 26.3% were measured, potentially stressing nondedicated circuits. In the temperature test, a positive correlation between the inverters power density and the touch temperature was found. The findings of this analysis provide insights for future standardization efforts and offer guidance to manufacturers in improving the safety of these PV systems.