Solar RRL最新文献

Covalent organic frameworks (COFs), are promising candidates for photoelectrochemical hydrogen evolution reaction (PEC HER). In this study, sp²-c COF photocathodes were synthesized on copper foam via Knoevenagel condensation polymerization, with the crystallinity systematically tuned by varying reaction conditions. By modulation, the alkalinity of the reaction system, crystallinity-related parameters were optimized, revealing significant variations in the structural integrity of the resulting sp²-c COFS. Under optimal synthesis conditions (110°C, 30 μL pyridine, 2 days), the photocathode demonstrated a photocurrent density of 60 μA cm⁻² at 0.3 V versus RHE, a value 2.5 times higher than that observed for samples with suboptimal crystallinity. These results emphasize the positive impact of increased crystallinity in improving PEC HER performance and provide insights for scalable photocathode design.

The high nonradiative energy losses (ΔE_nrs) in organic solar cells (OSCs) have become a huge obstacle for further improvements of their power conversion efficiencies (PCEs). To address it, the normal small molecule acceptor (SMA) is modified by attaching thiophene, 2-methylthiophene, and 2-chlorothiophene rings, respectively, on the terminals, giving three novel SMAs TIC, MTIC, and CTIC. With gradual increasing in the electron-donating capabilities of thiophene rings, these SMAs own more and more reduced intramolecular charge transfer (ICT) effects in the order of CTIC > TIC > MTIC. Reversely, the OSCs based on CTIC, TIC, and MTIC exhibit the monotonically increased electroluminescence quantum efficiencies (EQE_ELs) of 0.27%, 0.36%, and 0.44%, corresponding to lower and lower ΔE_nrs of 0.153, 0.145, and 0.140 eV, respectively. These values are all among the best ones for OSCs to date. Finally, when CTIC is introduced into PM6:BTP-eC9 binary system, the resulting ternary OSC delivers an improved open-circuit voltage (V_OC) of 0.864 V, thereby, a higher PCE of 18.82%. This study demonstrates that weakening ICT effects of SMAs is an effective strategy to realize smaller energy losses for OSCs.

Commercializing single-junction and tandem perovskite solar cells (PSCs) requires scalable, reproducible, and rapid deposition techniques. While spin coating is a commonly used method for fabricating lab-scale high-efficiency PSCs, large-area and uniform deposition with low material waste remains a challenge. This study explores a hybrid deposition method in which an inorganic PbI₂ precursor is deposited by vacuum evaporation followed by a solution process of organic halides. In particular, the impact of varying the PbI₂ deposition rate (R_d) over a wide range (0.03–2.84 nm s⁻¹) on material properties and the photovoltaic performance is investigated and compared with those by the conventional two-step spin-coating method. It appears that the R_d significantly influences surface morphology of the PbI₂ precursor films and the grain size/composition of the perovskite films. The optimal R_d of ∼0.7–0.8 nm s⁻¹ (∼6−7 min deposition) results in a large-grain-size perovskite and a power conversion efficiency (PCE) of over 20%, which exceeds that of the spin-coated reference PSC (19.1%). Notably, an increase of R_d up to ∼2–3 nm s⁻¹ (∼2 min deposition time) still maintains a comparable PCE of 18.8%. These results demonstrate the robustness of device performance against rapid inorganic precursor deposition, underscoring the potential of the hybrid deposition method for industrial-scale production.

Machine learning has emerged as a promising approach for estimating material parameters in solar cells. Traditional methods for parameter extraction often rely on time-consuming numerical simulations that fail to capture the full complexity of the parameter space and discard valuable information from suboptimal simulations. In this study, we introduce a workflow for parameter estimation in organic solar cells based on a combination of numerical simulations and neural networks. The workflow begins with the selection of an appropriate experimental dataset, followed by the definition of a device model that accurately describes the experiment. To reduce computational complexity, the number of variable parameters and their boundaries are carefully selected. Instead of directly fitting the experimental data using a numerical model, a neural network was trained on a large dataset of simulated results, allowing for efficient exploration of the high-dimensional parameter space. This approach not only accelerates the parameter estimation process but also provides valuable insights into the likelihood and uncertainty of the estimated parameters. We demonstrate the effectiveness of this method on organic solar cells based on the material systems PBDB-TF-T1:BTP-4F-12 and PM6:L8-BO, demonstrating the potential of machine learning for rapid and comprehensive characterization of emerging photovoltaic materials.

This perspective explores the transformative potential of atomic layer deposition (ALD) in fabricating high-performance tin dioxide (SnO₂) electron transport layers (ETLs) for perovskite solar cells (PSCs). ALD ensures conformal coatings with atomic-scale precision, reducing surface roughness and recombination sites while enhancing the structural and electronic properties of complementary SnO₂ layers. Furthermore, ALD's capacity to optimize energy-level alignment and foster high-quality perovskite crystallization improves charge transport, reduces trap-assisted recombination, and enhances device performance. Despite the advantages of ALD, most high-performance ALD SnO₂-based PSCs are combined with sol–gel deposition of SnO₂, chemical bath deposition of SnO₂, or nanoparticle SnO₂ (np-SnO₂), commonly referred to as bilayer ETLs. Bilayer ETLs address key challenges, including surface uniformity, defect mitigation, and energy alignment, which significantly impact PSC efficiency and stability. This perspective highlights the recent advances in ALD SnO₂/solution-processed SnO₂ (SP-SnO₂) bilayer ETLs in PSCs and explores the mechanisms for the superior photovoltaic performance of these bilayer approaches compared to single-layer ALD SnO₂. The perspective also identifies remaining challenges, including interface defects and scalability issues, and explores solutions like in situ passivation and interfacial engineering.

Defects originating from the ionic nature of perovskite film are major factors that degrade the performance of perovskite solar cells (PSCs), and mitigating or removing them is essential for the implementation of high-performance PSCs. Herein, an additive 4-toluenesulfonic acid ammonium salt (TAAS) has been used to modify the perovskite film. The sulfonic acid groups (SO₃⁻) as an electron donor can not only regulate the growth of perovskite crystals, but also effectively passivate the positively charged defects caused by under-coordinated Pb²⁺. The ammonium ions (NH₄⁺) can effectively passivate cation vacancies through electrostatic interactions. Furthermore, the benzene ring can trap trace I₂ generated by oxidation in the perovskite active layer and reduce the I₂-induced acceptor defects. The power conversion efficiency of PSCs based on the optimized perovskite is significantly improved from 24.70% to 26.02%, and the stability of PSCs is also advanced.

CsPbI₂Br is a promising material for efficient and stable perovskite solar cells (PSCs), owing to its excellent photothermal stability and suitable bandgap. However, severe energy band misalignment at interfaces combined with high interfacial and bulk defect densities critically limit device performance. In this work, we modeled CsPbI₂Br PSCs using SCAPS-1D and performed synergistic optimization of band alignment and defects. The procedure sequentially addressed the electron transport layer/perovskite (ETL/PVSK) interface, the PVSK/hole transport layer (HTL) interface, and bulk defects within the CsPbI₂Br layer. The obtained optimal parameters include a band offset of −0.3 eV and an interfacial defect density of 1.0 × 10¹⁰ cm⁻² for both interfaces (ETL/PVSK and PVSK/HTL), with a bulk defect density of 1.0 × 10¹³ cm⁻³. The optimized device achieved a V_OC of 1.544 V, a J_SC of 15.00 mA/cm², a fill factor (FF) of 87.22%, and a power conversion efficiency (PCE) of 20.20%. Mechanistic studies reveal that the optimal band offsets become more negative at low interfacial defect densities, facilitating carrier extraction and reducing recombination. Positive offsets lead to losses in quasi-Fermi level splitting (QFLS), with the ETL/PVSK interface being particularly sensitive to this loss mechanism. This study offers key design insights for high-performance CsPbI₂Br PSCs.

The study explored the role of doping Sr in double perovskite La₂NiMnO₆ to tune the bandgap of the host material thereby revealing a considerable decrease, indicating its usefulness in solar cell device fabrication. To authenticate the experimental findings revealing the bandgap tuning to 1.37 eV by Sr doping, close to 1.4 eV, an optimum value for achieving better efficiencies in solar cell devices, we focus on the performance analysis of Sr-doped based perovskite solar cell by performing the device optimization using LNMO and Sr-doped LNMO as the light-absorbing material in the SCAPS-1D simulation tool. The best SC configuration during device optimization turned out to be FTO/WS₂/LNMO/CFTS/C, where FTO was the substrate, WS₂ was the electron transport layer, LNMO was the absorber, CFTS was the hole transport layer, and C was the carbon contact. The SC was optimized for the thickness of all these constituent layers to obtain the best PV parameters. The impact of Sr-doped LNMO in the devices was very significant, as it enhanced the power conversion efficiency (PCE) from 13.90% in the pure LNMO to 19.62% in the Sr-doped LNMO, supporting the experimental results. The cell parameters of the Sr-doped-based optimized SC device were V_OC = 1.15 V, J_SC = 31.96 mA/cm², FF = 53.48%, and PCE = 19.62%, in comparison to those of the pure LNMO-based optimized SC device, which were V_OC = 1.35V, J_SC = 21.99 mA/cm², FF = 46.74%, and PCE = 13.90%, showing a considerable enhancement in the efficiency of the device. Significant variation in photovoltaic parameters with the density of defects of absorber layer reveals that the optimal doping along with minimum defect density is important to maximizing perovskite solar cell efficiency.

We report on sodium containing indium sulfide (In_xS_y:Na) buffer layer in combination with a Cu(In,Ga)Se₂ (CIGS) absorber and investigate the mutual interaction and influence of them on the thin-film solar cell device performance. We examine a variety of absorber layers including CIGS with RbF post-deposition treatment (PDT), CIGS without PDT, and Ag-alloyed CIGS without PDT, each with three different copper concentrations. All absorber layers are prepared by in-line coevaporation of the elements using a multistage industrially relevant process. The In_xS_y:Na buffer layers are deposited by magnetron sputtering from three different indium sulfide targets containing 0 mol%, 2 mol%, and 10 mol% NaF.

Devices in which the In_xS_y:Na layer is combined with CIGS with RbF-PDT have the highest power conversion efficiencies. The presence of sodium in In_xS_y can contribute to a higher cell efficiency depending on the quality of the absorber used. Sodium likely has a positive effect if the alkali doping in the absorber is insufficient and can be compensated by the sodium supplied from the buffer. We demonstrate cell efficiencies up to 19.1% with a sodium-free In₂S₃ buffer combined with a high-quality RbF-PDT CIGS absorber with a comparably high copper content.

Defect states at the boundaries and the perovskite/electron transport layer (ETL) interface critically induce charge recombination in printable mesoscopic perovskite solar cells (p-MPSCs). Herein, we engineer the defect management by introducing two multifunctional benzimidazole derivative additives, 1H-benzimidazole-2-carboxylicacid (2-CBIm) and 5-benzimidazolecarboxylic acid (5-CBIm), which are isomers with different functional group positions, for improving the performance of p-MPSCs. The functional group position differences modulate the defect passivation ability of 2-CBIm and 5-CBIm in p-MPSCs. 5-CBIm, featuring desired distribution of the carboxyl group and the imidazole group, presents superior binding with perovskite and the TiO₂ ETL than 2-CBIm, whose interaction ability is influenced by the steric effect. The enhanced interaction facilitates defect passivation and nonradiative recombination suppression in p-MPSCs. Consequently, the 5-CBIm device achieves a well-improved champion power conversion efficiency (PCE) of 20.61%, surpassing the 2-CBIm device (19.40%) and the control device (18.17%). This work contributes to a better understanding of structure–property relationships and opens extended possibilities for designing advanced defect passivation additives.