In perovskite solar cells (PSCs), the hole transport layer (HTL) is a crucial component, especially in inverted PSCs, which require enhanced cost efficiency, high mobility, excellent transmittance, and stability. The performance of inverted perovskite solar cells remains lower than the regular PSCs because of interfacial defects, poor electrical conductivity, and unfavorable band alignment between the perovskite and the HTL (NiOx). In this work, fluorine‐incorporated nickel oxide (F doped NiOx) NPs are prepared using a co‐precipitation approach and subsequently used as a HTL in the PSCs. Fluorine is effectively incorporated into the NiOx, resulting in strong bonding and a more stable structure, which passivates the hydroxyl groups from the NiOx surface and decreases defect sites. Moreover, fluorine is established as an efficient dopant for nickel oxide, which minimizes the formation of nickel vacancies while simultaneously enhancing the density of Ni3+ ions. Additionally, the electronic conductivity was enhanced, and the work function was increased with the F‐doped NiOx film, which can facilitate hole extraction and reduce the recombination rate. Therefore, the F‐doped NiOx PSCs achieved a remarkable power conversion efficiency of up to 20.78%. The F‐doped NiOx also lead to improvement in stability under several environmental conditions, such as air, light soaking, and heating (65°C).

Reliable and esthetically pleasing lightweight photovoltaic modules for building integration are expected to grow interest in the consumer market, especially for retrofitting older buildings and storehouses that are not structurally designed to withstand additional dead‐weight. The present work reveals the design of a novel module architecture attaining a total weight <6 kg/m2. The approach uses a highly transparent polymeric foil as the front pane and as an encapsulant to maintain optical coupling between the cell and the incident solar radiation, while the mechanical rigidity of module is maintained by the use of a composite backsheet, which consists of a polypropylene‐based honeycomb sandwiched between two layers of fiber reinforced skins. Two polypropylene skin variants were evaluated, with fiber densities of 820 and 660 g/m2. For esthetical improvement of the lightweight PV modules, a colored interlayer foil was used. Reliability testing included flexural bending and static mechanical load tests, environmental tests like, damp‐heat, ultraviolet radiation, thermal cycling, and humidity freeze. Several other critical tests, like hail‐impact test and fire‐ignition test, were also performed to check the potential of these architectures for building integration. The fiber density in skins of composite backsheets impacted the performance of modules against mechanical loads.

Dopant‐free carrier‐selective contacts have the potential to overcome parasitic absorption and doping‐related recombination associated with heavy doping. It offers a simpler preparation process and low‐temperature fabrication, which has attracted considerable research interest. This study demonstrated a novel full‐area dopant‐free cesium iodide (CsI, approximately 3 nm thick) as an electron‐selective and passivation contact for crystalline silicon (c‐Si) solar cells via thermal evaporation, achieving a champion power conversion efficiency of 21.75%. Desired Ohmic contacts, with contact resistivity around 3 mΩ·cm2, are formed between lightly doped n‐type c‐Si and metal electrodes (such as Ag, Al, and Mg) by inserting nanoscale CsI films. CsI film exhibits surprising insensitivity when in contact with the metal electrode. Furthermore, it is found that the thermal evaporation deposition CsI on n‐Si exhibits passivation properties at their interface due to the field passivation of n+‐n junctions and the chemical passivation of Si‐I bonds. Additionally, the stability of CsI is enhanced through thermal annealing, maintaining the stability of contact properties below 300°C. The CsI film offers a dual effect of selective carrier transport and reduced recombination, which simplifies the production process and expands the application of cesium‐based materials in photovoltaic devices.

Improving the performance of dye‐sensitised solar cells (DSC) under artificial light sources and at low light intensities requires preserving the adequate electron transport properties in the sensitised photoanode that are characteristic of DSC operation at 1 sun. Besides, parasitic resistance and optical losses must be reduced. In this respect, the impact of the chemical and electrical properties of the transparent conducting oxide (TCO) has somehow been overlooked. Considering the systematic reduction of the electron diffusion length as the low quasi‐Fermi level regime is approached, subtle variations of the properties of the TiO2 photoanode and its interaction with the TCO substrate can compromise optimal performance under indoor illumination. In this work, the performance of DSCs fabricated with commercial fluorine‐doped tin oxide (FTO) and indium tin oxide (ITO) substrates, as well as newly prepared ITO substrates of varying conductivity, has been analysed. Furthermore, a variation of the preparation conditions for the TiO2‐based photoanodes was conducted, with thermal treatments at two different annealing temperatures (450 and 550°C). Photovoltaic characterisation and analysis of the impedance response reveal a low conductivity of the substrate proves to be only adverse under 1 sun illumination, deteriorating the fill factor due to the series resistance voltage drop. In contrast, under low illumination intensity, all studied substrates show comparable performance, which can be attributed to the negligible voltage drop over the series resistance related to the significantly lower photocurrent. As a consequence, the conductivity of the TCO substrate is less critical when selecting a substrate for indoor applications. However, the choice of TCO affects the quality of TiO2 photoanodes, leading to shorter diffusion lengths in some cases. Interestingly, the annealing temperature plays a critical role in homogenising the differences observed while also enhancing the diffusion length, ensuring efficient electron collection under low light conditions.

Perovskite solar cells (PSCs) have become a groundbreaking technology in the field of photovoltaics, attaining unprecedented power conversion efficiencies (PCEs) of 27%. This achievement is attributed to extensive research in areas such as crystallization kinetics, solvent engineering, and interface optimization. Nonetheless, significant challenges persist in consistently replicating these record efficiencies, with many laboratories encountering difficulties in surpassing PCEs of 25% due to material sensitivity, inadequate control over the fabrication process, and the absence of detailed, reproducible fabrication protocols. In this study, we present comprehensive and reproducible fabrication protocols designed to achieve PCEs exceeding 25%. By disseminating our step‐by‐step protocols and critical experimental details, we aim to support non‐expert laboratories in attaining high efficiencies and facilitating the evolution of PSC technology. We assert that the open and transparent exchange of knowledge and experience is vital for fostering innovation and realizing the full potential of PSCs.

As global energy demands continue to rise, solar energy has emerged as one of the most promising alternative sources, drawing essential attention in scientific research. In particular, our study sought to explore whether the introduction of graphene could provide significant enhancements to the performance of solar cells. Within the experiment, poly(3‐hexylthiophene) (P3HT) was used as the donor material, while [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM or PCBM) served as the acceptor in the active layer of the solar cell. Graphene was substituted for PC61BM to evaluate its effect on solar cell efficiency. Bulk heterojunction (BHJ) solar cells with the FTO/TiO2/P3HT:PC61BM1–x:Grx/MoO3/Ag architecture were fabricated using spray and spin coating methods for x = 0, 0.01, 0.02, 0.03, 0.05, and 0.10. The power conversion efficiencies of the reference device (where x = 0 for Gr) and the device containing a graphene ratio of x = 0.10 were measured at 1.69% and 3.75%, respectively. This shows a substantial 2.2‐fold increase in efficiency with the incorporation of graphene into the system. Based on these findings, it is evident that graphene doping substantially improves the photovoltaic properties of the solar cells examined in this study, underscoring its potential in advancing solar cell technology.

While great progress is being made in achieving high power conversion efficiency (PCE), durability, and reliability in rigid and flexible n–i–p perovskite solar cells (PSCs), there is still room for improvement. Among myriad ways this can be achieved, one way is to improve the processing and quality of electron transport layers (ETLs) used in PSCs. To that end, here we explore the use of SnO2/TiO2 bilayer ETLs in both rigid and flexible PSCs. In the case of rigid PSCs, chemical bath deposition (CBD) is used where the bilayer architecture affords the CBD of high‐quality ETL, which results in PSCs with up to 25.13% PCE and operational stability T 80 (80% of initial PCE retained) of 2220 h under 1‐sun continuous illumination with maximum power‐point tracking. In the case of flexible PSCs, once again, the bilayer architecture allows us to fabricate high‐quality ETL using spin coating, which results in PSCs with up to 22.54% PCE and excellent mechanical durability, withstanding 20 000 bending cycles with ≈92% of the initial PCE retained. Mechanisms underlying the enhanced performance and stability/durability of rigid and flexible PSCs that use SnO2/TiO2 bilayer ETLs are elucidated. This approach could be extended to other ETL systems for PSCs for further improvements in PCE, durability, and reliability.

Extracting uranium from seawater at an ultralow concentration (3.3 ppb) is a promising approach for the sustainable development of nuclear energy, which presents a critical obstacle. Herein, we report a photothermal‐promoted extraction strategy by utilizing a self‐supporting covalent organic polymer‐based sponge (named TpPa‐SO3H@PU sponge) composed of black polyurethane sponge substrate and β‐ketoenamine covalent organic polymer with sulfonic acid groups. The adequate water transport induced by photothermal conversion significantly improves the mass transfer of uranyl ions. Compared with the dark condition, a 25.8% increase of uranyl extraction capacity, up to 36.4 mg g−1, is achieved under simulated sunlight irradiation. In 1 L of seawater, 83.8% of uranyl is extracted after exposure to natural sunlight for 48 h. Furthermore, 20 mL of concentrated solution containing 1 ppm uranyl is obtained from 9 L seawater after nine consecutive extraction‐elution cycles. These results demonstrate that TpPa‐SO3H@PU sponge holds significant potential for practical uranium extraction from seawater under natural sunlight.

Nitrogen‐functionalized graphene (N‐FG) derivatives are versatile materials with broad chemical applicability and straightforward preparation methods. N‐FG involves grafting nitrogen compounds onto graphene, categorized as ammonium hydroxide, amines, and quaternary ammonium salts. This review highlights N‐FG synthesis via chemical, thermochemical, electrochemical, and electromagnetic methods. It emphasizes N‐FG's role in photovoltaic (PV) technologies, particularly perovskite solar cells (PSCs) and dye‐sensitized solar cells (DSSCs). In PSCs, N‐FG excels as an interfacial layer, enhancing performance when in direct contact with perovskite films. In DSSCs, its applications include Pt‐free cathodes, photoanodes, and electrolyte additives, achieving power conversion efficiencies of 8–8.5%. The review also explores N‐FG's potential in other PV technologies, such as thin‐film and silicon solar cells, while addressing challenges and opportunities for advancing its role in sustainable energy solutions.