Solar RRL最新文献

The molecular structures and properties of donor and acceptor materials for organic solar cells (OSCs) determine their photovoltaic performance; however, the complex relationship between them has hindered the development of OSC materials. To study this, we constructed the database comprising 544 donor and non-fullerene acceptor pairs. Based on the principle of minimal rings and molecular units, each molecule in the database is cut into different fragments and defined as a new molecular fingerprint, where each bit corresponds to a fragment number in the molecule. Accordingly, the defined molecular fingerprint length is 234 and 723 bits for donors and acceptors, respectively. Random forest and extreme tree regression (ETR) are applied to predict the photovoltaic parameters, with ETR being the most effective. Through SHapley Additive exPlanations (SHAP) importance analysis, eight (10) important donor (acceptor) fragments are identified. Furthermore, by computing the cut fragment similarities with that of the important fragments obtained from SHAP analysis, fragments with similarity exceeding 0.6 are collected in order to design new molecules. By assembling the collected fragments, we designed 21 168 D-π-A-π-type donors and 1 156 400 A-π-D-π-A-type nonfullerene acceptors, generating 24 478 675 200 donor–acceptor pairs. Based on predictions using the trained ETR model, the highest power conversion efficiency reaches 13.2%.

Selenium alloying into a CdTe thin-film solar cell absorber has been one of the most significant advances in CdTe solar cell fabrication over the last decade. Oxygen plays a critical role in the CdSeTe deposition process, mainly to increase Se concentration in as-deposited CdSeTe films. However, it is hard to fabricate CdSeTe films with controllable Se concentration in a deposition chamber, which is usually filled with a certain atmosphere of O₂. In this work, we propose an alternative technique for Se alloying in CdSeTe films, that is, to pre-oxidize CdSeTe powder sources and then fabricate CdSeTe films in a O₂-free deposition chamber. The oxides formed on the oxidized CdSeTe source surface effectively suppress Te sublimation and hence increase Se concentration in the CdSeTe films. Furthermore, the presence of nonequilibrium, metastable hexagonal CdSeTe phase enhances Se incorporation into the CdTe films. The experimental results presented in this study demonstrate that using pre-oxidized CdSeTe powder source is a promising technique to control Se element in the form of graded distribution in highly efficient CdSeTe/CdTe thin-film solar cells. The highest cell efficiency achieved in this study is 16.4%.

Transparent superhydrophobic films/coatings have recently gained significant attention in the solar energy field due to their ease of preparation, low cost, self-cleaning process, and high effectiveness in reducing dust adhesion to the surface. Compared to the rigid glass cover, the organic one has an advantage of flexibility and light weight, but the dust deposition impact is more serious. The aim of the present study is to design a transparent and superhydrophobic film with good durability on the organic glass surface, to recover the module efficiency reduction caused by dust deposition. Based on a soft photolithography and hot-pressing process, periodic microcavities are prepared on the organic glass surface as an armor structure, and hydrophobic SiO₂ nanoparticles are sprayed into the microcavities to achieve anti-reflection and superhydrophobicity. The experimental test results show that the designed film possesses a large contact angle around 160°, a sliding angle of 3°, and a high visible transmittance over 90%. The unique armor structure design greatly improves the wear resistance of the film, and after encountering harsh conditions such as sandpaper friction, water flow impact, acid immersion, UV exposure, and repeatable bending, it still maintains excellent superhydrophobicity.

Ultrathin (Ag,Cu)(In,Ga)Se₂ (ACIGS) solar cells enable material savings, high manufacturing throughput, and application versatility. Moreover, the reduced absorber thickness relieves European concerns about critical raw material shortages. However, ultrathin device performance does not yet compete with their thicker counterparts due to increased rear contact recombination and incomplete light absorption. This work proposes a rear contact architecture that encapsulates a 25 nm Au patterned layer with 20 nm of Al₂O₃, increasing the rear contact reflectance while passivating the rear interface defects. However, one of several challenges with nanofabrication is aligning two nanopatterns. Therefore, the nanofabrication of the rear architecture is optimized to encompass one-step nanoimprint lithography without requiring alignment. Two ACIGS absorber growth temperature values of 550 and 450 °C are evaluated, with attention to their effect on rear architecture integrity. The rear contact remains intact when the absorber growth temperature is 450 °C. In such conditions, the proposed architecture increases the solar cell conversion efficiency by 1.5% abs. compared to a reference cell with Mo, resulting from a short-circuit current density gain of 3.7 mA cm⁻². Therefore, this rear contact architecture may greatly benefit the performance of ultrathin solar cells deposited at low temperatures.

A modified chemical surface deposition (mCSD) method was introduced to confirm the advantages of buffer layers deposited heterogeneously using a solution process mechanism. In chemical bath deposition (CBD), an absorber is immersed in a mixed aqueous solution containing all cation and anion precursors; in chemical surface deposition (CSD), only the absorber surface participates in the reaction using mixed precursor solutions; and in mCSD, each cation and anion precursor reacts separately on the absorber surface, resulting in a heterogeneous reaction. Optimum conditions to form a buffer layer via a heterogeneous reaction in the mCSD process are determined by changing the deposition order of the precursor solution and solution combination. The CdS or Zn(S,O,OH) buffer layers formed under optimal mCSD conditions indicated higher photovoltaic performance in solar cells compared to that of the conventional CdS buffer layer formed by the CBD method. Temperature-dependent photovoltaic characteristics, capacitance–voltage measurements, and drive-level capacitance profiling were performed to investigate carrier transport behaviors, confirming that the solar cell with mCSD-CdS had less interface recombination. Further, the admittance spectroscopy for defect analysis indicated that a solar cell with the mCSD-processed buffer layer did not form deep defects compared to that with the CBD-processed buffer layer.

Photostable and efficient 1.8 eV wide-bandgap (WBG) perovskites are needed for all-perovskite tandem photovoltaic (PV) applications, but the high bromine (Br) content can cause halide segregation. To achieve the same bandgap with a lower Br content, MAPbCl₃ can be added to form triple-halide perovskites. However, most triple-halide WBG perovskites are still fabricated by antisolvent spin coating with perovskite inks that cannot be transferred to scalable deposition methods. Furthermore, the role of the Cl additives on the bandgap and the photostability remains elusive. Here, Cl-additives, such as ACl, PbCl₂, and APbCl₃ (where A denotes MA, FA, Cs, Rb), are systematically investigated to form 1.8 eV triple-halide perovskites with 30 mol% Br by N₂-assisted blade coating. It is found that PbCl₂ and APbCl₃ can increase the bandgap by several tens of meV, while ACl can only increase the bandgap by few meV. CsPbCl₃ emerges as a promising alternative to MAPbCl₃, enabling 17.2% efficient MA-free 1.8 eV triple-halide perovskite solar cells (0.062 cm²) with enhanced phase- and photostability. Its scalability is demonstrated by slot-die coating a ≈10% efficient WBG perovskite solar module with an aperture area of 52.8 cm².

Accurate very short-term solar irradiance forecasting is crucial for optimizing the integration of solar energy into power systems. Herein, an image-based deep learning framework for minute-scale solar irradiance prediction is presented. The locally developed model is benchmarked against two commercial forecasting solutions deployed at the same experimental site, demonstrating superior accuracy and adaptability. A key contribution is the introduction of a skill-driven sampling algorithm based on clear sky index persistence error, which optimizes the training dataset by excluding low-utility samples while retaining essential physical features like solar zenith and azimuth angles. This algorithm enables the exclusion of up to 30% of the original training data, resulting in ≈16% savings in computational resources without affecting forecast accuracy validated using a test set of 324 991 observations. The model achieves a skill score of 7.63%, significantly outperforming the commercial models, which exhibit negative skill scores under the same conditions.

Photocatalytic CO₂ reduction is the use of solar energy to catalyze the conversion of CO₂ into a fuel with added value, and it is an effective way to reuse CO₂ to achieve carbon neutrality. In this study, NiAl–layered double hydroxides (LDH)/Bi₂Sn₂O₇–Ov/CuO–Ov composites with double oxygen vacancies are successfully prepared, and the effects of different component contents are investigated. The main products of the best sample NiAl–LDH/BSOv-40/CuOv-20 are carbon monoxide, methane, and ethane with yields of 29.95, 18.46, and 32.13 μmol g⁻¹ h⁻¹, respectively, and a selectivity of 68.15% for the C₂H₆ product. The evolutionary pathway and photocatalytic mechanism of CO₂ are investigated by in situ Fourier transform infrared spectroscopy and theoretical calculations. In this work, the scope of application of oxygen vacancy catalysts for C₂ production in the field of photocatalysis is broadened.

Infrared light management is crucial to maximize the optical performance of crystalline Si-based single junction and tandem solar cells. For this end, a low refractive index dielectric is typically inserted under the rear metal and an electrical contact is obtained locally through the dielectric. However, the realization of such an architecture can require numerous fabrication steps that are time and resource intensive. Herein, a simple approach is proposed in which commercially available, low-cost SiO₂ nanoparticles (NPs) are spin coated as rear reflectors on pyramid-textured Si, leaving the pyramid tips locally exposed for direct contact by an electrode without additional patterning. In Si heterojunction solar cells, complementing a 40 nm-thick indium tin oxide (ITO) layer with the SiO₂-NPs yields a gain of 0.3 mA cm⁻² in short-circuit current density compared to that obtained with a bare, 100 nm-thick ITO layer. Combined with reduced electrical losses, power conversion efficiency gains of 0.5%_abs to 0.3%_abs for single junction Si and perovskite-Si tandem cells are demonstrated, respectively. Finally, it is shown that the NPs can also be processed on large areas via blade coating and that the process can be further simplified by a change in the fabrication sequence of the SiO₂-NP and ITO layers.