Solar RRL最新文献

Perovskite solar cells (PSCs) have gained significant attention due to their high efficiency and potential for low-cost production. The upscaling of PSCs is key to its final large-scale commercial deployment. In recent several years, considerable advancements have been obtained on large-area perovskite solar modules (PSMs). Several large-area deposition methods have been employed to fabricate PSMs, mainly including spin-coating, doctor-blading, slot-die coating, meniscus printing, screen printing, and vacuum deposition. Among them, slot-die coating technique plays a critical role in preparing high-efficiency PSMs, which is most widely adopted until now. In this review, the fundamentals and important parameters of slot-die coating and its application in PSMs are first introduced. Then, the critical challenges and corresponding solutions are discussed. Finally, some potential development directions and issues are presented to advance the development of large-area perovskite photovoltaic devices toward practical application.

Flexible perovskite solar cells (FPSCs), featured with lightweight, high efficiency, and low cost, have attracted much attention anticipating in applications on wearable electronics, near-space vehicles, and internet of things. High efficiency and mechanical stability are two main factors in the study of FPSCs toward practical applications. In recent few years, many breakthroughs in materials modification and device innovation make the power conversion efficiency of FPSCs reach over 25%. A comprehensive review thus is conducted to elucidate the critical issues including flexible substrates, transparent electrodes, charge transport layers, perovskite films, and modifications for mechanical enhancement of FPSCs, which is expected to promote the future development of FPSCs.

Following the impressive efficiencies achieved for two-terminal perovskite/silicon dual–junction solar cells, perovskite/perovskite/silicon triple-junction cells have now gained attention and are rapidly developing. In a two-terminal triple-junction cell, maximizing the open-circuit voltage (V_OC) is not straightforward as it requires understanding and mitigating the dominant losses in such a complex structure. Herein, the high bandgap perovskite top cell is first identified as the main source of the V_OC loss in the triple-junction cell. A multifaceted optimization approach is then implemented that improves the V_OC of the 1.83 eV perovskite. This approach consists of 1) replacing the reference triple-cation/double-halide with a triple-cation/triple-halide perovskite, which improves perovskite bulk quality and reduces transport losses, and 2) implementing a piperazinium iodide passivation between the perovskite and the electron transport layer, which reduces nonradiative recombination losses at this interface. Employing these optimizations in the top cell of the triple-junction boost the V_OC by average 124 mV. A high V_OC of more than 3.00 V is achieved with a fill factor of 79.6%, a short-circuit current density of 9.0 mA cm⁻², and an efficiency of 21.5%. Further study is conducted on the improvement of V_OC in the triple-junction solar cell using subcell selective photoluminescence-based implied V_OC imaging, which is applied for the first time to a perovskite-based triple-junction structure.

The advancement of semitransparent organic solar cells utilizing narrow bandgap donor and acceptor materials has progressed rapidly in recent years. These semitransparent devices exhibit high absorption in the near-infrared range and high transmission in the visible region, offering broad application potential. This research suggests employing dual ultrathin metal films as transparent electrodes to fabricate semitransparent photovoltaic devices. The investigation focuses on the spectral simulation and modulation of the transparent electrode structure, film thickness, optical coupling layer, and 1D photonic crystal utilizing the optical transfer matrix method. The primary goal of the integrated optical effects is to enhance the light absorption in the active layer while maintaining device visible transparency. Simulation results indicate the feasibility of a device structure consisting of Nb₂O₅/Ag/Nb₂O₅/PM6:BTP-eC9:L8-BO/MoO₃/Ag/ZnSe/Na₃AlF₆/ZnSe, achieving an expected short-circuit current density ($��J_{�\text{sc}�}�$) of 17.10 mA cm⁻², an average visible transmittance (AVT) of 50.40%, and a light utilization efficiency (LUE) of 5.49%. The incorporation of three nonperiodic dielectric layers shows the potential to further increase $��J_{�\text{sc}�}�$, AVT, and LUE to 17.40 mA cm⁻², 51.49%, and 5.71%, respectively. This study introduces a novel device structure that optimizes active layer absorption and visible transmittance, aiming to advance semitransparent photovoltaic devices.

Inorganic perovskite exhibits an appropriate bandgap and excellent light and thermal stability, making it an ideal top-cell material for silicon tandem solar cells. However, significant non-radiative recombination losses due to surface defects in inorganic perovskite films, along with phase stability issues in humid environments, restrict the efficiency improvement of inverted inorganic perovskite solar cells (IPSCs). This work reports the preparation of efficient, stable inverted IPSCs by using a multifunctional molecule, bis (pentafluorophenyl) zinc (BPFz), as surface treatment for CsPbI_2.85Br_0.15 films. After treatment with BPFz, the inorganic perovskite film undergoes secondary grain growth, significantly increasing grain size. Simultaneously, BPFz can passivate undercoordinated Pb²⁺, effectively suppressing nonradiative recombination. Additionally, the fluorinated phenyl group endows the inorganic perovskite film surface with superhydrophobic properties, protecting the perovskite layer from the influence of environmental humidity, while also helping to suppress ion diffusion within the device, enhancing device stability. Ultimately, after surface treatment with BPFz, the efficiency of inverted IPSCs increases from 18.18 to 20.22%, and V_OC increases from 1.169 to 1.231 V, with excellent moisture and thermal stability. This work provides a new approach for the development of high-efficiency and stable IPSCs in the future.

Perovskite-based solar cells have been extensively studied by the scientific community over the past decade and they are currently a very promising technology to be integrated into tandem perovskite module, for example, associated with silicon solar cells. However, one of the challenges lies in the upscaling of the production of perovskite solar cells from small laboratory-scale cells (<1 cm²) to larger modules. In this context, there is considerable interest in extending the analysis previously conducted on a micrometer or millimeter scale to a larger scale. In this work, for the first time, full-sample size hyperspectral absolutely calibrated photoluminescence (PL) imaging applied to 16 cm² perovskite semitransparent mini-modules is introduced. Herein, the inhomogeneities in PL emission observed between the different cells are investigated, highlighting shunt mechanisms and ion migration effects, as well as quantifying and evaluating the origins of the voltage losses. The impact of these inhomogeneities on device performance and stability is also addressed.

Molecular engineering serves as a prevalent strategy in solar cells architecture toward robust, reliable, and highly efficient light-electricity conversion devices. Specifically, two well-known strategies, i.e., halogen substitution and π-spacer modification, are extensively introduced. However, the underlying photovoltaics mechanism on benzodithiophene terthiophene rhodamine (BTR) remains lacking. Herein, a combined approach of density functional theory (DFT) and time-dependent DFT calculations is systematically introduced to unravel the implication in terms of structure–property relationships. The results suggest that halogen substitution on BTR molecular backbone can effectively reduce the frontier molecular orbital energy levels of molecule. Moreover, extending the π-spacer can increase the conjugation length of the molecular backbone, which results in improving the photoelectric properties of small molecules. B₃, i.e., the addition of a pair of thiophene rings to the π-spacer of the BTR, with the lowest energy gap and reorganization energy, relatively small exciton binding energy, and the strongest light absorption spectra, is a promising candidate for the donor molecule. In addition, by combining these two modification strategies (i.e., chlorinated B₃), the overall performance of the new B₃-Cl molecule can be further improved compared to B₃. The findings provide a theoretical guidance for the rational design of novel A–π–D–π–A-type small molecules.

Interface engineering plays a crucial part in optimizing the device performance in perovskite solar cells (PSCs). Herein, ammonium sulfamate (ASA) is introduced as a multifunctional additive into SnO₂ electron transport layer (ETL) with a “three birds with one stone” strategy. At first, the oxygen vacancy and hydroxyl ligand on the surface of SnO₂ nanoparticles causing charge recombination is efficiently reduced by incorporating ASA into SnO₂ colloidal dispersion. Second, the coordination bond of SO₃⁻ anion in ASA with SnO₂ and the interaction between NH₂ in ASA with Pb²⁺ construct a chemical bridging at the interface of ETL/perovskite. It significantly enhances the interfacial electron transport. Third, the introduction of ASA is conducive to form high-quality perovskite films with larger crystallite size and improved crystallinity due to the optimization of buried interface. Consequently, by the integrated effects on both interfaces and the bulk, the ASA-based device delivers an increased efficiency from 20.73% to 24.41%. Moreover, the ASA optimized device displays a remarkable retention of over 90% of its original power conversion efficiency after 1000 h under a controlled N₂ atmosphere, demonstrating the stability is significantly enhanced.

A new non-fullerene small-molecule acceptor (NFSMA), designated as TDPT-TBA, is synthesized. This molecule is based on an S,N-heteroacene central core connected to a weakly electron-withdrawing end group, 1,3-diethyl-2-thiobarbituric acid. In these findings, it is suggested that incorporating an sp²-hybridized nitrogen atom into a fused cyclopentadiene framework, rather than utilizing a sp³-hybridized carbon atom, can lead to a more effective NFSMA and potentially enhance the performance of organic solar cells. The TDPT-TBA exhibits an upshifted lowest unoccupied molecular orbital energy level of −3.76 eV when compared to the Y6 acceptor. Additionally, there are complementary absorption spectra between both the polymer Poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b′] dithio-phene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione))] (PBDB-T) and Y6. Organic solar cells utilizing the PBDB-T:TDPT-TBA blend achieves a high open-circuit voltage of 0.942 V, yielding a power conversion efficiency (PCE) of 13.72%. When TDPT-TBA is incorporated into a PBDB-T:Y6 binary active layer, the optimized ternary organic solar cells reach a PCE of 16.06%, surpassing the efficiency of the binary PBDB-T:Y6 configuration, which is 13.51%, under identical processing conditions. The increase in PCE can be attributed to several factors, including the utilization of excitons generated in TDPT-TBA via energy transfer to Y6, a longer charge carrier lifetime, shorter charge extraction times, increased crystallinity, and denser stacking distance. These factors collectively contribute to reduced carrier recombination and improved charge transport.

Inverted perovskite solar cells (IPSCs) have become a research hotspot in the field of photovoltaics due to their excellent photovoltaic performance, minimal hysteresis, and low fabrication costs. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), as an inexpensive hole transport material, has been widely applied in IPSCs. However, PEDOT:PSS has drawbacks such as energy-level mismatch with perovskite, severe interfacial defects, low hole transport rate, and low conductivity. Therefore, modifying and improving PEDOT:PSS is of practical value. Herein, potassium benzoate is introduced to dope PEDOT:PSS, enhancing its conductivity and accelerating hole transport in the device, making the energy levels between PEDOT:PSS and perovskite more compatible. More importantly, potassium benzoate-doped PEDOT promotes crystal growth, increases the grain size of the perovskite film, and passivates interfacial defects. The open-circuit voltage (V_oc) of the device increases from 1.107 to 1.137 V, and the power conversion efficiency improves from the original 17.24% to 20.15%. This study provides a new approach to develop inverted PSCs.