Solar RRL最新文献

The degradation of perovskite solar cells due to reverse bias (RB) is one of the remaining challenges hindering the commercialization of the technology. To overcome this challenge, a thorough understanding of and control over the breakdown (BD) voltage are crucial. A prerequisite for this is that the community “speaks the same language,” that is, that the reported BD voltages are comparable. A review of literature data shows that the impact of measurement parameters is often unknown and seems to depend strongly on sample properties. It follows that standardization is the only way to reach comparability. Here, a set of measurement parameters to fill this gap is proposed. Additionally, various definitions of a “BD voltage” are used in parallel without any way of relating them to each other; this metric and its determination need to be considered as well. After a thorough discussion of the available definitions, the use of the point of maximum curvature is introduced. Its main advantage is the possible connection to an analytical description of the BD mechanism. In this way, a starting point for scientists new to the field of RB stability is provided, and the ground for a broader discussion in the community is prepared.

Like other carbon nanoparticles, diamond nanoparticles, also known as nanodiamonds (NDs), tend to aggregate when they are dispersed in solution or when they are cast on a substrate. This is mainly due to the versatility of functional groups present on their surface. Previous studies have reported the use of several techniques, including chemical modification, surface active compound usage, and mechanical milling using tiny zirconia beads, for destroying the ND aggregates. Herein, we focus on the deposition of hydrogen-terminated NDs (H-NDs) for use as electron transport layer material in inverted organic solar cells and we investigate different approaches to prevent or to eliminate aggregation during the coating of films of H-NDs, including the reduction of the ND concentration in the dispersions and the blending of H-NDs powder with additives or binders such as styrene-butadiene rubber, carboxymethyl cellulose, a combination of both, fluoride-based polyvinylidene fluoride, and the conjugated polyelectrolyte poly(9,9-bis(3′-(N, N-dimethyl)-N-ethylammonium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene))dibromide (PFN-Br), in dispersions. The film morphology and more specifically the device's performance and stability were improved in several cases and single nanoparticles of diamonds with small sizes (<20 nm) were observed.

The grain boundaries of perovskite films prepared by the solution method are highly disordered, with a large number of defects existing at the grain boundaries. These defect sites promote the decomposition of perovskite. Here, we use ribavirin obtained through bacillus subtilis fermentation to regulate the crystal growth of perovskite, inducing changes in the work function and energy level structure of perovskite, which significantly reduces the defect density. Based on density functional theory calculations, the defect formation energies of V_I, V_MA, V_Pb, and Pb_I in perovskite are improved. This increases the open-circuit voltage of perovskite solar cells (PSCs) (ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag) from 1.077 to 1.151 V, and the power conversion efficiency (PCE) increases significantly from 17.05% to 19.86%. Unencapsulated PSCs were stored in the environment (humidity ≈35 ± 5%) for long-term stability testing. After ≈900 h of storage, the PCE of the ribavirin-based device retains 84.33% of its initial PCE, while the control-based device retains only 13.44% of its initial PCE. The PCE of PSCs (ITO/SnO₂/perovskite/Spiro-OMETAD/Ag) is increased from 20.16% to 22.14%, demonstrating the universality of this doping method. This universal doping strategy provides a new approach for improving the efficiency and stability of PSCs using green molecular doping strategies.

In this study, the reproducibility of perovskite solar cell (PSC) performance is improved through ethylenediammonium (EDA²⁺)-based surface treatments. By substituting iodide in EDAI₂ with larger anions, such as thiocyanate (SCN^–), tetrafluoroborate (BF₄ ⁻), and hexafluorophosphate (PF₆ ⁻), we significantly increased the solubility of EDA²⁺ in isopropyl alcohol (IPA), thereby enhancing the reliability of the compositions at the working concentrations by avoiding the risk of unwanted precipitation. In p–i–n-type lead-based PSCs, the standard deviation of power conversion efficiency (PCE) was reduced from 2.1% with EDAI₂ to 0.7% with EDA(SCN)₂, 0.7% with EDA(BF₄)₂ and, 0.4% with EDA(PF₆)₂. The high solubility of EDA(PF₆)₂ in low-polarity solvents such as ethyl acetate facilitated damage-free surface modifications, as demonstrated by successful application to mixed tin–lead PSCs. These findings show how tailored anion substitution in EDA²⁺ solutions enhances the consistency and performance of PSC surface treatments.

Enhancing the light-absorption ability of ZrO₂ by reducing the bandgap is important for the development of high performance solar-driven catalyst. This study systematically investigates the effects of Ce doping and thermal reduction on the bandgap of ZrO₂ by experiments and density functional theory (DFT) calculations. The results demonstrate that both Ce doping and thermal reduction facilitate the formation of oxygen vacancies (O_V) through distinct mechanisms, ultimately leading to the bandgap reduction of ZrO₂. As X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Raman, and electron paramagnetic resonance revealed, Ce doping can induce the cell distortion of ZrO₂. Zr3Ce1p exhibits the largest crystal structure transition, indicating that the low percentage of doped Ce can exert the greatest influence on the ZrO₂ cell structure. Furthermore, thermal reduction can strongly affect the surface of samples and directly raise the O_V concentration. As UV–vis spectra revealed, the synergistic strategy can minimize the bandgap of ZrO₂ (5.03 eV) to 1.87 eV (Zr3Ce1Ca2), showing a 62.8% decrement. Meanwhile, Zr3Ce1Ca2 shows the fastest degradation of methylene blue (24.73%) under light conditions without a sacrificial agent, higher than ZrO₂ by 242%. The valence band-XPS spectra and DFT results demonstrated that the downward extension of the conduction band bottom is the main reason for the bandgap shortening.

During the crystallization of perovskite, a large number of internal and interfacial defects are generated, posing significant challenges to the performance of perovskite solar cells. A novel chelating strategy using 1,1^′-carbonyldiimidazole (CDI) is proposed to reduce interfacial nonradiative recombination and provide defect passivation through synergistic passivation with PEABr. The bidentate imidazole group in CDI binds to the uncoordinated Pb²⁺ at the upper interface, while the C–N, C=N, and C=O functional groups act as chelators to interact with uncoordinated I⁻, mitigating the negative impact of PEABr on the interfacial morphology during the formation of the 2D interface. This effectively bridges the perovskite and PCBM interfaces, improves interfacial contact, and promotes charge transfer. As a result, the CDI-modified device achieves a power conversion efficiency improvement of 24.41%, with a V_OC of 1.180 V, J_SC of 25.21 mA cm⁻², and fill factor of 82.07%. Additionally, the unencapsulated device exhibits enhanced long-term stability, maintaining 95% and 90% of its initial efficiency after 1000 h at 25°C in a nitrogen atmosphere and 600 h under humid air conditions, respectively.

Wide-bandgap perovskite solar cells (WBG PSCs) have emerged as transformative photovoltaic technologies, achieving certified efficienciesexceeding 24.53% and enabling perovskite/silicon tandem cells with record-breaking 34.58% performance. Despite these advances, their commercialization remains constrained by intrinsic material instabilities—defect proliferation, interfacial energy mismatches, and halide segregation—that conventional single passivation strategies fail to address comprehensively. Recently, multiple passivation strategies have demonstrated unprecedented improvements in efficiency and operational stability by simultaneously targeting multiple degradation pathways, surpassing the limitations of isolated optimizations. This review systematically explores recent advances in defect passivation, energy-level alignment, and phase segregation suppression for WBG PSCs, with a focus on three synergistic dimensions of multiple passivation: (i) multifiled passivation (synergistic chemical/electrical/optical fields), (ii) multisite passivation (grain boundary/surface coordination), and (iii) multi-interface passivation (top/buried interface optimization). Multiple passivation strategies establish an efficient roadmap for advancing WBG PSCs. Future investigations should aim to develop theoretical frameworks to elucidate and balance competing versus cooperative passivation mechanisms, ultimately optimizing synergistic effects to approach the Shockley–Queisser efficiency limit.

This review provides a comprehensive understanding of the critical role of interface engineering in enhancing the efficiency and stability of mixed Sn–Pb perovskite solar cells (PSCs). We primarily focus on the p–i–n architecture, systematically addressing the fundamental challenges and recent strategic breakthroughs at both the top exposed perovskite surface and the bottom buried interface. By detailing how surface engineering approaches mitigate interfacial defects and optimize charge-carrier dynamics, this review emphasizes the direct correlation between precise interface control and the rapid performance enhancement in narrow-bandgap single-junction devices. Furthermore, we extend this discussion to the interconnecting layers in all-perovskite tandem solar cells, where interfacial optimization is crucial for achieving effective charge transport. Ultimately, this review offers strategic perspectives on overcoming current interfacial hurdles to facilitate the transition of Sn–Pb PSC technology from laboratory-scale research to large-scale industrial applications.

The escalating CO₂ concentration and energy demand necessitate efficient CO₂ conversion strategies. Photothermal catalytic CO₂ methanation is a promising strategy, yet its efficiency is hindered by the inherent stability of CO₂ and the rapid recombination of photogenerated charge carriers. Among non-noble metal catalysts, Ni-based catalyst is a promising candidate for CO₂ methanation, with sintering and agglomeration remaining to be addressed. Herein, NiMn/TiO₂ bimetallic catalysts with varying Ni/Mn ratios were synthesized to overcome these issues. Characterization results demonstrate that Mn incorporation enhances CO₂ adsorption capacity by increasing oxygen vacancies and significantly improves the separation efficiency of photogenerated carriers. Furthermore, Mn doping optimizes the electronic structure of the catalyst, narrowing its bandgap for improved light absorption. But the catalytic performance is highly dependent on the Ni/Mn ratio. The synergistic effect of Ni and Mn can be maximized when the Ni/Mn ratio is 1:1, which is specifically manifested as the best catalytic activity. Excessive Mn loading covers active Ni sites and impedes electron transfer, thereby degrading activity. Therefore, this work highlights the importance of Mn as a promoter in designing efficient non-noble metal catalysts for photothermal CO₂ conversion.