Solar RRL最新文献

Despite the rapid progress of organic solar cells (OSCs) with an efficiency over 20% based on morphology optimization, the efficiency of aqueous/alcohol nanoparticle (np)-based OSCs is still stuck at about 10% without synchronized growth using the same optimization approach. The efficiency gap is mainly due to the fact that conventional morphology optimization strategies for solution-cast devices cannot be directly adopted for nanoparticle-based devices. To illustrate, we first adopt one means of morphology optimizationdifferent molecular weight (Mn) of polymer to investigate mechanism of morphology modulation in nanoparticle films. The organic solution-cast devices show similar performance based on different Mn of polymer, while aqueous np-based devices occur large difference. The interaction of good/non solvent in nanosuspension synthesis process and long crystal growth period during np-film formation process can magnify the aggregation behavior. The magnification behavior is also verified by additive optimization strategy. Strategies used for solution-cast devices that pursue high regularity, tend to easily cause excessive phase separation in np-based devices. Rational phase separation with small-sized domain is more important than high ordering for np-devices. The results help to understand the morphology modulation on np-film and provide a sensible guide for future optimization in np-OSCs.

Until recently, bulky ammonium cations, or 2D cations, one of the most promising avenues for interface passivation, have been applied almost exclusively to the p-type interface of the n-i-p architecture. As the perovskite photovoltaics community gradually moves toward the inverse architecture (p-i-n), the question of whether to integrate 3D/2D interfaces at the interface between perovskite and the N-type contact layer is only natural. By comparing different integration strategies, this work highlights the importance of solvent engineering and additive strategies to integrate quasi-2D perovskite in p-i-n devices. It is demonstrated that these strategies enable almost complete conversion of lead iodide (PbI₂) excess through its conversion to quasi-2D phases, result in a quasi-Fermi level splitting (QFLS) gain of up to 40 meV, and promote the emergence of quasi-2D phases of higher dimensions, which are less detrimental to electron extraction. Increasing device efficiency and stability using 2D cations, however, remains a challenge for the p-i-n architecture due to the quasi-2D phases’ intrinsic properties and interfacial mechanical stress at the nanoscale. It is anticipated that, to take full advantage of quasi-2D perovskites’ superior stability and passivating power, one needs to gain control over the homogeneity, thickness, and phase of the low-dimensionality layer.

The societal acceptance of building integrated photovoltaics (BIPV) is strongly linked to their visual appearance. In this regard, efforts have been devoted to the design of colored photovoltaic modules that can be esthetically blended into the roofs and façades of buildings. Distributed Bragg reflectors (DBRs), periodically intercalating nonabsorbing dielectric materials with contrasting refractive indices, are one of the most promising technologies currently explored to produce a broad range of vivid structural colors with minimal optical losses. However, DBRs usually exhibit strong color variation with respect to the angles of incident and reflected light, which is undesirable for BIPV applications. To minimize such iridescence, while avoiding the increased design complexity associated with the currently implemented textured substrates, here we developed an alternative approach, relying on an optimization-based inverse design methodology, to identify nontrivial planar nanometer-thin layer configurations capable of reproducing different target colors on demand with low angular color dependence. As we demonstrate, these optimized structures consistently outperform the conventional periodic DBRs, meeting the target colors with minimal angular variations in hue, regardless of the color selected, and with very low effect on the photovoltaic performance. Therefore, the proposed approach constitutes a promising route for the design of next-generation colored BIPV.

Carbon-based materials provide transformative solutions to address the key challenges of cost, stability, and scalability in perovskite solar cells (PSCs). This review explores the diverse roles of carbon-based materials (including graphite, carbon black, carbon nanotubes, graphene derivatives, fullerene derivatives, and carbon quantum dots) as high-performance alternatives in functional layers. As electrodes, carbon-based materials replace costly noble metals while providing high chemical stability, hydrophobicity, and mechanical flexibility, thereby enhancing device stability under harsh thermal and humid conditions. For charge transport layers, the incorporation of carbon-based materials improves carrier mobility, suppresses trap-assisted recombination, and optimizes Interfacial energy band alignment. Additionally, the carbon-based intermediate layer effectively promotes charge extraction, passivates interface defects, and improves interface contact. The compatibility of carbon-based materials with low-temperature solution-processing techniques highlights their potential for large-scale production. This review assesses the state-of-the-art, material design strategies, and performance of carbon-based PSCs, and outlines future directions toward high-efficiency, stable, and commercially viable devices.

Effective photovoltaic module recycling is essential for improving the sustainability of solar technologies and securing the silver supply chain. One method of recycling silver from end-of-life photovoltaic modules is electrodeposition following nitric acid leaching. This study investigates how nitric acid concentration affects the electrochemistry and recovery of silver in a controlled three-electrode system. Silver recovery and Faradaic efficiency were found to increase with acid concentration from 0.1 м. Maximum values of 97% silver recovery and 96% Faradaic efficiency at 4.0 м nitric acid were observed using a silver working electrode at constant current deposition of −20 mA/cm². Past this point, both recovery and efficiency were observed to decline sharply due to enhanced silver dissolution kinetics. It was also found at low nitric acid concentrations (<2.0 м) silver oxynitrate formed as a solid deposit at the counter electrode, while at higher concentrations (>2.0 м) silver (II) complexes formed but remained dissolved in the electrolyte. Industrially, a nitric acid concentration in the range of 2.0–4.0 м is recommended to optimize silver recovery and efficiency while minimizing anode fouling in a full cell arrangement.

The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has reached 27.18%, benefiting from the rapid advance of self-assembled monolayers and fine manipulation of crystallization kinetics of perovskite. However, the further development of PSCs is hindered by the lagging electron transport layers (ETLs) that fullerene ETLs are dominated. To tackle this problem, great efforts have been devoted to improving the properties of fullerene ETLs, such as enhancing defect passivation, tuning energy levels, suppressing self-aggregation, and so on, for elevating the efficiency and stability of PSCs. In this review, the recent advances in fullerene ETLs are summarized. For thermal-evaporation deposited fullerene ETLs, the thickness and thermal annealing are identified as key factors to be optimized, and novel multifunctional fullerene derivatives are developed. For solution-processed fullerene ETLs, new fullerene derivatives and effective methods are developed to address the issues that impede the PCE and stability of PSCs. This review aims to provide an overview and deep understanding of fullerene-based ETLs for PSCs. Finally, the strengths and drawbacks of these two film-deposition methods are discussed from a commercial perspective, and possible strategies for further development of fullerene ETLs are provided.

Self-assembled molecules (SAMs) have emerged as a promising hole transport layer in inverted perovskite solar cells (PSCs), owing to their advantages of low cost, tunable energy level alignment, ultrathin nature, and excellent interface passivation properties. This review systematically examines recent advancements in SAMs for optimizing inverted PSCs. We begin by discussing the typical configuration of SAMs and highlight key optimization strategies: molecular design, co-SAM engineering, and post-treatment techniques. The modulated anchoring behavior along with molecular packing of SAMs is emphasized, as well as corresponding impacts on performance. Additionally, SAM modifications have been shown to significantly enhance buried defect passivation and regulate the crystallization kinetics of perovskite films, leading to substantial improvements in PSC performance. Finally, we provide insights into the future directions for SAM development, aiming to fully realize their potential in perovskite photovoltaics.

Single-junction Pb–Sn perovskite solar cells with a 1.24 eV bandgap have recently achieved power conversion efficiencies exceeding 23%, driven by advances in absorber passivation and interface engineering. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is widely used as a hole transport layer (HTL) due to its favorable conductivity and hole selectivity. However, its water-based processing is incompatible with inert glovebox conditions and can degrade the underlying perovskite in all-perovskite tandem architectures. Furthermore, the acidic and hygroscopic nature of PSS compromises long-term device stability, particularly for narrow-bandgap absorbers. To address these issues, an anisole-based PEDOT:PSS formulation (HTL4) with reduced PSS content was employed. X-ray photoelectron spectroscopy revealed modified surface composition, enhancing hydrophobicity and perovskite film formation. Steady-state photoluminescence measurements of narrow-bandgap perovskite films deposited on the modified HTL exhibited a 60 mV increase in implied open-circuit voltage (iV_OC) compared to reference devices. Single-junction solar cells utilizing the modified HTL showed up to a 6% absolute efficiency gain, attributed to reduced series resistance and improved fill factor, as confirmed by Suns-V_OC and current–voltage analysis. Maximum power point tracking demonstrated enhanced stabilized efficiencies. All-perovskite tandem solar cells incorporating HTL4 exhibited both increased iV_OC and overall performance, outperforming tandem devices employing the standard HTL.

We investigate the perimeter losses in each sub-cell of a small area 2-terminal perovskite-silicon tandem device with poly-Si on oxide based bottom cell passivation. We vary the shaded diode areas by patterning them on the solar cell or using different aperture masks during J–V measurement. By numerical device simulations, we reveal a perimeter-induced open-circuit voltage reduction from 1912 to 1858 mV for our device geometries of 1 cm² aperture area on 6.25 cm²-sized silicon bottom cells. The largest part of ΔV_OC = 26 mV is attributed to recombination in the shaded silicon wafer. A V_OC loss of 14 mV is attributed to the shaded poly-Si diode. The shaded perovskite top cell induces a V_OC loss of 14 mV, if the perovskite total area is 1.44 cm² as in our current device. Our so far best in-house measured efficiency is 26.7%. Simulations show, that implementing our improved perovskite top cell and front fingers can increase the efficiency by about 2.6%_abs. and omitting the perimeter losses additional 1.2%_abs.. The investigation shows that shading losses are significant and thus have to be taken into account when experimentally assessing the efficiency potential of tandem cells on small area devices.

Buried interface imperfections and uncontrolled crystallization dynamics remain critical challenges that hinder the efficiency and long-term stability of perovskite solar cells (PSCs). In this work, we present a molecular interface engineering strategy using potassium pyrophosphate (KPP) as an interlayer between the titanium dioxide (TiO₂) electron transport layer and the perovskite absorber. The bifunctional nature of KPP enables phosphate group anchoring onto TiO₂ and K⁺-mediated passivation of undercoordinated Pb²⁺ and I⁻ ions, simultaneously improving interfacial contact and suppressing nonradiative recombination. This interfacial coordination facilitates crystallization of perovskite films with larger grain sizes, reduced surface roughness, and suppressed PbI₂ residue, as confirmed by a series of analyses. As a result, KPP-modified PSCs exhibit a champion power conversion efficiency of 24.70%, with an enhanced open-circuit voltage of 1.17 V and minimal hysteresis. Furthermore, the devices maintain 83% of their initial efficiency after 1000 h of continuous operation under AM 1.5G illumination at the maximum power point. This study highlights the potential of buried interface coordination in simultaneously optimizing crystallization, defect passivation, and device stability, offering a promising and scalable approach toward high-performance perovskite photovoltaics.