Layered lead‐free halide double perovskites (LDPs) have emerged as promising candidates for environmentally benign and intrinsically stable photovoltaic absorbers. Despite their chemical robustness and compositional flexibility, their power conversion efficiencies remain well below those of Pb‐based perovskites. This discrepancy arises from a combination of intrinsic electronic structure constraints, defect‐driven nonradiative recombination, processing‐induced inhomogeneity, and device‐architecture mismatches. In this review, we systematically examine performance limitations in LDPs and emerging solutions that can overcome these fundamental obstacles. We dissect four interdependent bottlenecks, namely, (1) electronic and excitonic limitations arising from reduced dimensionality and heavy carrier effective mass mismatches, (2) defect physics and self‐trapping phenomena, (3) synthesis and thin‐film processing challenges, and (4) interface and device‐level losses. For each category, we discuss emerging mitigation strategies, including band engineering, defect passivation, crystallization control, and interface optimization. By consolidating insights into a unified diagnostic perspective, we aim to provide a roadmap toward overcoming performance limitations in LDP photovoltaics.
Organic photovoltaics (OPV) is one of the new solar energy technologies, which offers various benefits including short energy payback time, lightweight, flexibility, and semitransparency.Recent development progress has attracted substantial scientific and commercial interest. Nevertheless, challenges include scalability and stability, necessitating larger efforts to improve the processability and long‐term stability of solar cells. This study focuses on the device's long‐term stability, specifically on stabilizing the morphology of the photoactive layer. An amphiphilic molecule, p ‐toluene sulfonic acid (TSA), was used as an additive to improve both performance and stability by controlling the morphology of P3HT:PCBM solar cells.
In recent years, organic–inorganic halide perovskite solar cells (PSCs) have rapidly emerged as one of the most promising third‐generation photovoltaic technologies, due to their high‐power conversion efficiency (PCE), low cost, and solution processability. The device performance and PCE depend on the architecture of PSCs and interfacial properties. Further, improvements in PCE are largely driven by minimizing nonradiative charge recombination, often caused by defects in metal halide perovskites. This review focuses on how heterocyclic compounds containing N, O, S, NS, and NO, affect grain boundaries, inhibit nonradiative recombination, and improve photovoltaic performance as molecular passivators. Finally outlines, the guidelines for selecting suitable heterocyclic compounds as passivating agents and offers perspectives on future strategies to further advance passivation approaches and overall device performance.
The rational design and construction of efficient donor–acceptor (D–A) architectures represent a pivotal strategy for enhancing photocatalytic activity, particularly toward boosting solar‐driven hydrogen evolution performance. To further modulate the electron transfer pathway at the donor–acceptor (D–A) interface, a supramolecular composite (THPP/C 60 ‐NH 2 ) is rationally designed and synthesized using tetrahydroxyphenylporphyrin (THPP) and amino‐functionalized fullerene (C 60 ‐NH 2 ) as building blocks. Benefiting from the strong electron‐donating characteristic of THPP and the excellent electron‐accepting capability of C 60 ‐NH 2 , as well as the directional hydrogen bonding interaction between amino groups and porphyrin hydroxyl groups, this system realizes efficient and precise intermolecular electron transfer. The long‐lived charge‐separated state generated in the composite effectively suppresses carrier recombination and enhances photogenerated carrier separation efficiency. The obtained THPP/C 60 ‐NH 2 exhibits a high photocatalytic H 2 production activity of 15.86 mmol g −1 h −1 , approximately 2.7 times that of pure THPP, providing a new route to regulate D–A interfacial kinetics through polar group modification.
Developing efficient semiconductor catalysts for the photocatalytic synthesis of hydrogen peroxide remains intrinsically challenging, primarily because the rapid recombination of photoinduced charge carriers limits reaction efficiency. In this work, an S‐scheme Nb 2 O 5 /Bi 2 WO 6 (Nb/BiW) heterojunction is rationally engineered to overcome these intrinsic limitations and markedly enhance photoinduced charge separation. Systematic experimental investigations demonstrate that integrating Nb 2 O 5 with Bi 2 WO 6 broadens light‐harvesting capability, increases accessible surface area, and creates abundant interfacial charge transport channels, thereby facilitating efficient carrier migration and providing a high density of redox‐active sites. The optimized Nb/BiW‐1.5 heterojunction exhibits superior photocatalytic performance, delivering an H 2 O 2 production rate of 4525 μmol g −1 h −1 within 60 min under simulated solar irradiation (AM 1.5). In parallel, the catalyst maintains excellent durability, sustaining catalytic efficiency over 10 successive reaction cycles. Mechanistic analysis, supported by comprehensive physicochemical characterizations and control experiments, reveals that the built‐in internal electric field inherent to the S‐scheme junction plays a pivotal role in directing charge separation and transfer while preserving strong redox potentials. These findings elucidate fundamental aspects of H 2 O 2 photosynthesis in Nb/BiW systems and provide a general design framework for next‐generation photocatalysts for solar‐driven chemical synthesis.
Interfaces play a central role in perovskite solar cells (PSCs), governing charge extraction, recombination dynamics, and operational stability. Precise interfacial engineering is therefore essential for enabling efficient carrier transport, suppressing nonradiative recombination, and prolonging device lifetime. Nevertheless, persistent interfacial challenges, including defect accumulation, energy‐level mismatch, ion migration, and thermomechanical degradation arising from thermal expansion mismatch, remain major barriers to further improvements in both efficiency and durability. This review systematically summarizes recent advances in interfacial engineering for PSCs, with particular emphasis on the underlying physicochemical principles. Progress in the engineering of top interfaces, buried interfaces, and vertically integrated dual‐interface strategies is comprehensively discussed. Finally, future opportunities and challenges for realizing highly efficient and robust PSCs under large area fabrication and harsh operating conditions are highlighted.
Double-cable polymers (DCPs), consisting of covalently conjugated organic semiconducting polymer electron donors (D) and nonfullerene electron acceptors (A), have emerged as promising single-component D-A photoactive materials. The photoactivities of DCPs are, however, capped by their intrinsic chemical nature. Herein, we demonstrate that the light harvesting and energy conversion capabilities of DCPs can be augmented by interfacing them with functional additives without changing their chemical nature. A DCP consisting of polythiophene (PTh)-perylene diimide (PDI) D-A components is interfaced with the reduced graphene oxide (rGO) as functional additive to produce PTh-PDI-DCP/rGO hybrid. Fluorescence spectroscopy, cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy performed as a function of varying wt.% of rGO reveal the charge transfer between the components of PTh-PDI-DCP/rGO and suggest that the optimum rGO content in the hybrid is 15 wt.%. As photocatalyst in the artificial photosynthesis of H2O2, the PTh-PDI-DCP/rGO hybrid exhibits an H2O2 generation rate of 120.8 +/- 3.1 & micro;M mg-1 h-1 averaged over 10 photocatalytic cycles, which are 3.3, 2.4, 3.5, 1.5, 1.4, and 2.6-fold enhancements compared to rGO, P3HT, PDI, PTh-PDI-DCP, P3HT/rGO, and PDI/rGO, respectively. Overall, this work offers a new avenue to expanding the design space of photoactive materials through strategic interfacing of DCPs with rationally selected functional additives.
Understanding the interplay of multiple material parameters is essential to approaching the theoretical efficiency limits of inverted perovskite solar cells (PSCs). In this work, we employ a technology computer‐aided design framework coupled with the transfer matrix method (TMM) to evaluate the efficiency limits of p–i–n PSCs. Our simulations identify a tolerance window for interfacial band alignment, showing that field‐assisted tunneling enables efficient carrier extraction despite moderate energy offsets. Furthermore, we derive quantitative relationships between the power conversion efficiency (PCE) and intrinsic properties, including carrier mobility, lifetime, and doping concentration. Based on these dependencies, we propose a diagnostic formula using the bottleneck principle to estimate the PCE potential relative to the Shockley–Queisser limit. This framework serves as a theoretical tool to identify performance bottlenecks, providing clear design rules for screening materials and optimizing high‐efficiency PSCs.
The development of high-efficiency crystalline silicon (c-Si) heterojunction solar cells is contingent on the engineering of efficient carrier transport layers. Molybdenum oxide (MoOx) emerges as a promising dopant-free hole transport layer (HTL) material for c-Si solar cell fabrication, owing to its high work function and wide bandgap. However, dangling bonds on the silicon surface cause the reduction of the open-circuit voltage (V oc) and fill factor (FF) of the solar cell. MoOx-based solar cells face issues such as oxygen vacancies and parasitic absorption. These problems hinder performance improvement by reducing the separation of photogenerated carriers, ultimately limiting the increase in power conversion efficiency (PCE). In this work, nitrogen-hydrogen annealing effectively reduces silicon surface dangling bond density, while optimized MoOx thickness minimizes parasitic absorption. These modifications enhance solar cell performance, increasing open-circuit voltage from 721.7 to 731.7 mV and improving fill factor from 74.58% to 80.01%. The results demonstrate the potential of MoOx as an efficient HTL for high-performance crystalline silicon solar cells. The cell achieves a remarkable PCE of 23.96%. This study explores the potential application of MoOx as an HTL in n-type c-Si solar cells and provides valuable insights for the design of high-performance solar cells.
Uranium extraction from ocean is crucial for the utilization of nuclear energy, especially for the sustainable development of nuclear power plants. The extra low concentration of U(VI) ions in the presence of other organic/inorganic coexisted chemicals and marine microorganism in ocean restricts the separation of U(VI) efficiently. The highly selective sorption of U(VI) and further photocatalytic chemical transformation of adsorbed U(VI) ions to U‐containing precipitates (UO 2 , UO 2 )(O 2 )·nH 2 O or other compounds) could continuously extract U(VI) from natural seawater. In the sorption‐photocatalytic strategy of U(VI) preconcentration from ocean, the fast sorption of U(VI) with high selectivity, efficient sunlight absorption, photocatalytic generation separation of e − –h + pairs, and excellent antibacterial properties are the most important challenges for high U(VI) photocatalytic separation from seawater. In this minor review, the main methods for each challenge are described from the authors’ viewpoint, which may be helpful to synthesize photocatalytic materials and to optimize technical proposal in U(VI) extraction from ocean.
Biphasic catalytic systems enhance photocatalytic degradation by improving mass transfer and reaction kinetics, with polymeric carbon nitride (PCN) being a promising material despite limitations like charge recombination and poor interfacial compatibility. To address these issues, fluorine‐modified PCN has emerged as an effective solution, synergistically optimizing amphiphilicity and electronic structure for improved biphasic photocatalysis. The construction strategies for fluorine‐modified PCN (F‐PCN) primarily encompass in situ fluorine doping and surface fluorination. The stabilized Pickering emulsion photocatalytic system based on F‐PCN capitalizes on distinctive interfacial effects, enabling efficient enrichment and activation of hydrophobic organic pollutants in the oil phase while promoting rapid transfer of polar intermediates to the aqueous phase. This dynamic mass transfer process effectively mitigates product inhibition, providing critical insights for the development of advanced multiphase photocatalytic systems. In the photocatalytic degradation of Sudan red, the optimized F‐PCN catalyst demonstrated exceptional performance, achieving a degradation efficiency of 96.79% within 40 min. Furthermore, due to enhanced charge carrier separation and increased electron transport efficiency induced by fluorine modification, the photocurrent response intensity of F‐PCN was 3.2 times greater than that of pristine PCN, further confirming its superior photocatalytic performance.
The increasing demand for clean water intensified research into solar desalination as a sustainable and energy‐efficient approach for freshwater production. Recent developments in the field of 3D printing provide new opportunities to overcome the limitations of conventional solar evaporator designs by enabling the fabrication of tailored, multifunctional structures. While traditional solar stills typically produce 2–5 l/m 2 /day of fresh water, 3D‐printed interfacial heating systems demonstrated significantly enhanced performance, achieving up to 4.36 kg/m 2 h under one‐sun illumination. The review emphasizes the role of additive manufacturing in designing photothermal materials, usage of innovative solar evaporators such as Janus evaporators, volcanic evaporators, tripodal porous wood‐mimetic evaporator, palisade solar evaporator, chiral torsion, and hierarchical porous and optimizing evaporator geometries. This review also highlights the salt‐repellent and self‐cleaning features of the evaporators to enhance evaporation efficiency and long‐term stability. Furthermore, key challenges, like material durability, print resolution, scalability, and long‐term reliability, are critically discussed, along with potential solutions through high‐performance polymers, nanocomposites, and emerging 4D printing strategies. The review concludes that additive manufacturing not only provides design flexibility and rapid prototyping but also has the potential to speed up the development of scalable and robust solar desalination technologies that can tackle global water scarcity.
As a historic photovoltaic material with a wide bandgap (~1.9 eV), selenium has regained research interest for indoor photovoltaics due to its spectral match with indoor light sources. This review summarizes recent advances in the material properties, fabrication techniques, and device engineering of Se‐based solar cells. Se combines attractive practical merits, including earth abundance, low toxicity, intrinsic environmental stability, and compatibility with low‐temperature processing. However, the one‐dimensional structure of its ideal photovoltaic phase—trigonal selenium—poses challenges for controlling thin‐film orientation. Through the development of various preparation techniques, such as close‐space sublimation and melt processing, combined with interface engineering (e.g., forming Se–O bonds, introducing Te adhesion layers) and transport‐layer optimization, the certified efficiency of Se solar cells has reached 10%. Notably, under indoor illumination, Se cells have achieved efficiencies of over 20% and have been successfully used to power Internet‐of‐Things devices, demonstrating considerable application potential. Continued optimization of film quality and device architecture are expected to expand Se photovoltaics toward flexible electronics and tandem integration.
The power conversion efficiency (PCE) of organic solar cells (OSCs) has surpassed 21%; however, their long-term stability remains constrained by ultraviolet (UV)-induced degradation of the active layer, while the underutilization of UV photons further restricts the efficiency potential. To address these issues, a dual-functional UV-converting interfacial modifier, 2-(2H-benzotriazol-2-yl)-6-(dodecyl)-4-methylphenol (UV571), was utilized to integrate photon down-conversion with active interface optimization. The benzotriazole core of UV571 absorbs UV photons through photoinduced tautomerism and transfers the energy to the donor polymer through F & ouml;rster resonance energy transfer, efficiently converting UV light into visible light. Concurrently, the incorporation of a long alkyl chain serves to adjust the surface energy and enhance its miscibility with the active layer. This dual-functional strategy has been shown to optimize hole transport by suppressing pinhole defects and enhancing charge-transport kinetics. It also markedly mitigates UV-triggered active layer degradation. Consequently, binary OSCs based on the D18:BTP-eC9 system deliver an excellent PCE of 20.36%, along with significantly improved photostability, while the ternary OSCs (D18:BTP-eC9:L8-BO) achieve a higher PCE of 20.61%. This work successfully transforms an environmental stressor into a performance enhancer, emphasizing the crucial role of interfacial engineering in enhancing stability and providing a pragmatic approach to high-performance OSCs.
