Wide-bandgap perovskite absorbers are essential for achieving high-efficiency perovskite/silicon tandem solar cells. However, in p-i-n architectures, their inherent strong p-type (or weak n-type) characteristics hinder electron extraction, causing significant open-circuit voltage (V OC) deficits. To address these challenges, we developed 3-phthalimidopropanoic acid (DPA). This molecular passivation material leverages the electron-deficient properties of its phthalimide core. DPA delivers three synergistic effects: it acts as an interface dipole layer to precisely align surface energy levels, enhance the surface n-type characteristics, and boost quasi-Fermi level splitting (QFLS); it forms a gradient distribution during anti-solvent processing to modulate crystallization kinetics, improve film morphology, and minimize defects; and it achieves carboxyl-group chelation of undercoordinated Pb2+ to effectively passivate surface and bulk traps, thereby significantly enhancing device stability. Consequently, a DPA-modified wide-bandgap (1.68 eV) perovskite solar cell achieves an efficiency of 22.91%. Moreover, a two-terminal perovskite-silicon tandem solar cell delivers an efficiency of 31.66%. This approach provides a robust strategy for efficient and stable tandem photovoltaics, advancing n-type interface engineering.

Flexible perovskite solar cells (FPSCs) suffer from strain localization-induced mechanical degradation, primarily due to heterogeneous strain distribution at grain boundaries. Herein, we propose a molecular engineering approach involving a crosslinked Methacrylic anhydride (MA) to construct a 3D crosslinking network within perovskite films. This molecular-scale network effectively redistributes localized strain into a more homogeneous pattern, as indicated by reduced strain variance and a lower Young's modulus. Simultaneously, the MA network modulates crystallization kinetics, leading to enlarged grain sizes, enhanced (001) orientation, and decreased defect density. Together, these effects minimize strain concentration and promote elastic strain release, thereby suppressing microcrack formation at grain boundaries. As a result, the optimized rigid perovskite solar cells exhibit superior conversion efficiency of 26.42%, while the FPSCs reach 25.03% with excellent mechanical stability.

Lead halide perovskite solar cells (PSCs) based on the CsFAMAPbI1-xBrx system have achieved high efficiencies. However, residual lead iodide (PbI2) often precipitates on the film surface, forming secondary impurity phases. These phases accelerate halide ion migration and Schottky defect formation. Additionally, excess Pb2+ ions can interact with MA+, FA+, and I-vacancies, generating deep-level defects that impair device performance. To address these challenges, we fabricated perovskite films with a bandgap of 1.62 eV using a two-step sequential deposition method and employed a cleaning and healing protocol based on polar/nonpolar solvents. By optimizing additives (MAI, MABr, or MACl) and temperature, we effectively eliminated residual PbI2 on the surface of perovskite films. Wide-bandgap PSCs treated with MAI (or analogous compounds) achieved power conversion efficiencies (PCE) exceeding 20 %. This demonstrates the effectiveness of our mixed-solvent approach in producing high-quality perovskite films, thereby enhancing device performance and stability.

Spiro-OMeTAD is one of the most widely used organic hole-transporting material (HTM) for perovskite solar cells (PSCs). Owing to its intrinsically low conductivity, LiTFSI is typically employed as a dopant to increase its conductivity and facilitate hole extraction. However, LiTFSI typically relies on prolonged air oxidation for activation and exhibits strong hygroscopicity, which significantly degrades device the performance and lifetime. In this study, we attempted to incorporate a series of organic alkyl thiol compounds with different chain lengths into the Spiro-OMeTAD film to improve the performance of PSCs. Both short-chain alkyl thiols (1,2-Ethanedithiol, EDT; 1,4-Butanedithiol, BDT) and long-chain alkyl thiols (1-Dodecanethiol, DDT; Octadecanethiol, ODT) are found to (i) coordinate with Pb2+ at the perovskite/Spiro-OMeTAD interface and grain boundaries, thereby passivating defects, and (ii) construct a hydrophobic surface barrier that suppresses moisture ingress, leading to synergistic improvements in photovoltaic performance and stability. Benefiting from bidentate coordination enabled by an optimal SH spacing of approximately 2.5 Å, the short-chain EDT enabled the devices to achieve a reverse-scan power conversion efficiency (PCE) of 21.30%, with an open-circuit voltage (VOC) of 1.19 V and a peak external quantum efficiency (EQE) approaching 90%. In contrast, the long-chain DDT formed an efficient hydrophobic barrier, allowing the unencapsulated devices to retain over 70% of their initial efficiency after 1080 h of storage at 80 ± 5% relative humidity (RH) and 25–35 °C.

The single-source vapor deposition (SSVD) technique offers a simple, low-cost route with great potential for large-scale fabrication of perovskite films. However, it often yields inhibited nucleation, leading to interfacial voids, pinholes, and inhomogeneous grain growth. To address this, a CsCl seed layer with island-like growth characteristics was introduced into the substrate prior to the SSVD of FAPbI(3) powders to improve film formation. This layer serves as an interfacial buffer, providing abundant nucleation sites and reducing buried interfacial defect density. This seed layer engineering enables controlled nucleation and uniform crystal growth, resulting in dense, homogeneous perovskite films with suppressed nonradiative recombination. Consequently, the photovoltaic performance of the devices is significantly improved, achieving a power conversion efficiency (PCE) of 20.26%, compared to 17.82% for the control. Moreover, the unencapsulated devices retain 85.3% of their initial efficiency after 1000 h of aging under 40-50% relative humidity at similar to 25 degrees C. This work provides an effective and scalable interfacial engineering strategy to enhance the performance and stability of single-source vapor-deposited perovskite solar cells, paving the way for high-efficiency, large-area perovskite optoelectronics.

ABSTRACT Achieving uniform self‐assembled monolayer (SAM) deposition on nickel oxide (NiO x ) and suppressing interfacial defects caused by high‐oxidation‐state nickel species remains a challenge for inverted perovskite solar cells (PSCs). Here, we develop a surface modification strategy using cesium oxalate (CsOA) to synergistically regulate the NiO x /SAM buried interface. The CsOA treatment suppresses detrimental Ni 4+ content and chelates with Ni 3+ to form the complex [Ni(C 2 O 4 ) 3 ] 3− , which maintains a stable oxidation state of Ni 3+ and inhibits its continuing redox reactions as a result of the enhanced conductivity and p ‐type characteristics. Moreover, as a buffer layer, CsOA can prevent high‐oxidation‐state nickel species (Ni ≥3+ ) from reacting directly with the perovskite in uncovered regions and passivate buried perovskite defects through the interaction of the oxalate ion and under‐coordinated Pb 2+ . Additionally, the enhanced anchoring between SAM and NiO x /CsOA promotes uniform SAM assembly, thereby improving film quality and stability. As a result, the optimized NiO x /CsOA/SAM HTL enables inverted PSCs with efficiencies of 22.89% (1.67 eV) and 26.48% (1.54 eV), retaining 85.7% of the initial efficiency after 1560 h under AM1.5G illumination at 65°C. A scalable mini‐module (an active area of 11.0 cm 2 ) achieves an efficiency of 23.45%, highlighting the approach's potential for high‐performance, stable, and industrially viable PSCs.

Organic–inorganic hybrid perovskite solar cells (PSCs) have shown tremendous promise due to their excellent optoelectronic properties and cost-efficient fabrication. However, the efficiency of traditional lead halide PSCs is approaching the Shockley–Queisser limit, prompting interest in tin-lead perovskite solar cells (Eg ≈ 1.25 eV) as a candidate for tandem configurations with the potential to surpass this limit. A key challenge lies in optimizing the hole transport layer (HTL), as widely used PEDOT:PSS suffers from high acidity and poor crystallinity, hindering device performance. In this work, we used a formic acid modification of PEDOT:PSS to enhance its conductivity, energy band alignment, and crystallinity. Acid treatment promotes proton transfer, reducing insulating PSS chains and improving phase separation, thereby facilitating efficient hole transport. Tin–lead perovskite films fabricated on formic acid-treated PEDOT:PSS (Fa-PEDOT:PSS) exhibit improved crystallinity, larger grain size, and reduced defect density. Devices incorporating Fa-PEDOT:PSS demonstrate enhanced photovoltaic performance, achieving a power conversion efficiency (PCE) of 21.87% with reduced hysteresis and excellent stability, retaining ∼90% of initial efficiency after 1600 h in an inert atmosphere. These findings highlight the potential of acid-treated PEDOT:PSS as an optimized HTL for tin–lead PSCs, paving the way for high-efficiency, environmentally friendly photovoltaic technologies.

In recent years, perovskite/silicon tandem solar cells have emerged as a research hotspot in the field of solar cells. For high-efficiency tandem solar cells, the crystallinity and defect control of the wide-bandgap perovskite absorber layer are crucial. Herein, FA0.8Cs0.2Pb(I0.8Br0.2)3 wide-bandgap perovskite films with a bandgap of 1.67 eV are developed using phthalic anhydride-tert-butyloxycarbonyl (BD-Boc) as an additive. The resulting films exhibit improved quality, enhanced crystallinity, reduced bulk defects, improved phase stability, and reduced residual surface stress. Time-resolved photoluminescence (TRPL) and photoluminescence (PL) analysis revealed that the films exhibit low non-radiative recombination (NRR) losses and a high average carrier lifetime. Based on the above FA0.8Cs0.2Pb(I0.8Br0.2)3 perovskite thin film modified with BD-Boc, the wide-bandgap single-junction perovskite solar cells achieved a champion power conversion efficiency (PCE) of 22.92%, an open-circuit voltage of 1.22 V, and a fill factor of 83.47%. Furthermore, using the BD-Boc-modified wide-bandgap perovskite single-junction cell as the top subcell, a perovskite/crystalline silicon tandem solar cell with a designated active area of 1 cm2 was fabricated, which achieves a PCE of 28.47%.

[4‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl)butyl]phosphonic acid (Me‐4PACz) consistently exhibits inhomogeneous distribution on the substrate, which makes it a challenge for the growth of high‐quality perovskite film, resulting in undesired interfacial losses at buried interfaces. Moreover, the flexible alkyl chains of Me‐4PACz are not conducive to intermolecular interactions and hinder charge flow. Here, a novel molecule with 4‐Methoxy‐N‐(4‐methoxyphenyl)‐N‐phenylaniline (TPA) and carbazole backbone, named CzTPA is designed, which constituted Co‐SAM with Me‐4PACz. The two carboxyls on the end of carbazole will act as an anchoring group to cover the inadequate coverage of Me‐4PACz on the NiO x . The methoxy group on the TPA can passivation the uncoordinated Pb 2+ at the perovskite buried interface by the interaction of Pb─O. Additionally, the Me‐4PACz can be restrained self‐aggregation by interacting with the TPA group of CzTPA. The cooperation of CzTPA realizes the more homogeneous distribution of Me‐4PACz on the NiO x , efficient charge transport, and minimize buried interfacial defects. Accordingly, the CzTPA modification can significantly enhance the efficiency of 1.54‐eV PSCs from 23.53% to 25.66% and sustain 91.4% of its original efficiency after 1992 h under continuous illumination at 65 °C. More importantly, a 1.68 eV of wide‐bandgap PSC achieved a PCE of 22.75% with good photostability.

The emergence of metal halide perovskite materials has triggered a revolutionary change in optoelectronic devices. Due to their outstanding optoelectronic properties and defect tolerance, metal halide perovskites can be used for a wide range of applications, including perovskite solar cells (PSCs), perovskite light-emitting diodes (PeLEDs), and perovskite photodetectors. However, the performance of perovskite-based optoelectronic devices is constrained by severe charge recombination at the interfaces between the perovskite film and charge transport layers. Self-assembled monolayers (SAMs) are attractive for addressing these interfacial issues. SAMs exhibit notable cost-effectiveness while providing superior optoelectronic characteristics, with potential for enhancement via tunable molecular engineering and optimization of ion-dipole interactions. Here, we review the recent advances of SAMs in perovskite-based optoelectronic applications by elucidating their role and function in different devices. Then we summarize the structure-function-performance relationships between SAMs and devices based on recent research. Finally, we provide a perspective on the role of SAMs in promoting practical applications by effectively improving the interfacial properties of perovskite-based optoelectronic devices.

Wide bandgap (WBG) NiO X -based perovskite solar cells demonstrate significant potential for achieving efficient and stable perovskite/silicon tandem solar cells. Nevertheless, the enhancement of device efficiency continues to be constrained by severe interface defects, inadequate hole extraction, and a substantial energy level mismatch between the NiO X hole transport layer (HTLs) and the perovskite layer. Here, we propose an interface engineering strategy involving the mixture of [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid and [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid as Co-SAM modified NiO X HTLs. This approach effectively suppresses nonradiative recombination at the HTL/perovskite interface, and the finely optimized energy-level arrangement significantly facilitates hole extraction at the interface. As a result, the 1.68 eV inverted WBG perovskite solar cell with Co-SAM-modified NiO X exhibited an impressive efficiency of 21.6%, with an open-circuit voltage of 1.19 V and a fill factor of 81.2%, as well as excellent long-term stability under one solar illumination. This study provides valuable insights for addressing the challenge of the NiO X /perovskite buried interface and realizing high-performance and durable perovskite cells.

Wide-bandgap perovskites (WB-PVKs) are highly promising materials for tandem photovoltaic applications, yet their practical performance is significantly hindered by critical issues such as non-radiative recombination and photo-induced phase segregation. Herein, we report a dual-passivation strategy utilizing phenylethylammonium chloride (PEACl) and 1,3-diaminopropane dihydroiodide (PDADI) to simultaneously enhance crystallinity and reduce defect density in 1.68 eV WB-PVK films. The passivation layers were fabricated via a scalable doctor-blading technique under ambient conditions, achieving power conversion efficiencies exceeding 16% over a large active area of 64.624 cm2. PEACl and PDADI together reduced surface defects, suppressed 2D-phase formation, and increased grain size from 450 to 850 nm. Moreover, the defect density at the perovskite/electron transport layer interface decreased by approximately 27%, leading to a notable enhancement in device efficiency from ∼15% up to a maximum of 16.05%. These results demonstrate that the developed dual-passivation method effectively addresses both photovoltaic performance and phase stability issues, providing a scalable and industrially viable approach toward the fabrication of high-efficiency wide-bandgap perovskite solar modules.

Large-area fabrication of alpha-FAPbI3 perovskite solar modules (PSMs) faces challenges in achieving uniform crystallinity and minimizing grain boundary defects. Herenin, a CsPbBr3 seed layer was introduced onto the NiOx hole transport layer (HTL) via vacuum evaporation prior to perovskite film deposition using a vapor-blade coating method. Synchrotron-based in situ GIWAXS analysis revealed that the CsPbBr3 seed layer effectively modulates the crystallization kinetics of PbI2, facilitating the transition from delta-phase to alpha-phase perovskite and yielding films with superior crystallinity, grain size, and structural orientation. This seed layer also enhances the conductivity of NiOx, improves charge transport efficiency, and reduces recombination losses. As a result, large- area PSMs (active area: 61.56 cm2) incorporating the CsPbBr3 seed layer achieved a power conversion efficiency (PCE) of 20.02 %, compared to 17.62 % for pristine devices. Additionally, these encapsulated modules exhibited excellent ambient stability, maintaining over 80 % of their initial performance after 1100 h under 60 % relative humidity. This study highlights the potential of CsPbBr3 seed layer engineering as a scalable and effective strategy for industrial production of high-efficiency, stable perovskite solar modules.

Inverted perovskite solar cells (PSCs) are preferred for tandem applications due to their superior compatibility with diverse bottom solar cells. However, the solution processing and low formation energy of perovskites inevitably lead to numerous defects at both the bulk and interfaces. We report a facile and effective strategy for precisely modulating the perovskite by incorporating AlOx deposited by atomic layer deposition (ALD) on the top interface. We find that Al3+ can not only infiltrate the bulk phase and interact with halide ions to suppress ion migration and phase separation but also regulate the arrangement of energy levels and passivate defects on the perovskite surface and grain boundaries. Additionally, ALD-AlOx exhibits an encapsulation effect through a dense interlayer. Consequently, the ALD-AlOx treatment can significantly improve the power conversion efficiency (PCE) to 21.80 % for 1.66 electron volt (eV) PSCs. A monolithic perovskite-silicon TSCs using AlOx-modified perovskite achieved a PCE of 28.5 % with excellent photothermal stability. More importantly, the resulting 1.55 eV PSC and module achieved a PCE of 25.08 % (0.04 cm2) and 21.01 % (aperture area of 15.5 cm2), respectively. Our study provides an effective way to efficient and stable wide-band gap perovskite for perovskite-silicon TSCs and paves the way for large-area inverted PSCs.

To maximize the power conversion efficiency (PCE) and stability of perovskite/silicon tandem solar cells (TSCs), high‐performance and stable perovskite top cells with wide‐bandgaps are required. A 2D/3D wide‐bandgap perovskite with a bandgap of 1.69 eV using 1H‐1,2,4‐triazole‐1‐carboximidamide (1‐TzFACl) as a spacer is developed. The 2D/3D wide‐bandgap perovskite shows better film quality, enhanced crystallinity, suppressed nonradiative recombination, and significantly improved phase stability. Its initial PCE (21.58%) remains above 87% after 1560 h of continuous illumination due to the insertion of Cl − in the perovskite lattice. A monolithic two‐terminal perovskite/silicon TSC achieves a PCE of 25.66% with high light stability. This work provides an ingenious strategy to restrain the phase segregation in wide‐bandgap perovskites, leading to effective and stable perovskite/silicon TSCs.

The pursuit of highly efficient and stable wide-band gap (WBG) perovskite solar cells (PSCs), especially for monolithic perovskite/silicon tandem devices, is a key focus in achieving the commercialization of perovskite photovoltaics. In this study, we initially designed poly(ionic liquid)s (PILs) with varying alkyl chain lengths based on density functional theory calculations. Results pinpoint that PILs with longer alkyl chain lengths tend to exhibit more robust binding energy with the perovskite structure. Then we synthesized the PILs to craft a hydrophobic hydrogen-bonded polymer network (HHPN) that passivates the WBG perovskite/electron transport layer interface, inhibits ion migration and serves as a barrier layer against water and oxygen ingression. Accordingly, the HHPN effectively curbs nonradiative recombination losses while facilitating efficient carrier transport, resulting in substantially enhanced open-circuit voltage (Voc ) and fill factor. As a result, the optimized single-junction WBG PSC achieves an impressive efficiency of 23.18 %, with Voc as high as 1.25 V, which is the highest reported for WBG (over 1.67 eV) PSCs. These devices also demonstrate outstanding thermostability and humidity resistance. Notably, this versatile strategy can be extended to textured perovskite/silicon tandem cells, reaching a remarkable efficiency of 28.24 % while maintaining exceptional operational stability.

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells. The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs. In this work, we adopted a solid–liquid two-step film formation technique, which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films. This method possesses the advantages of integrating vapor deposition and solution methods, which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform, large-area perovskite film. Furthermore, modification of the NiO x /perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization. As a result, a large-area perovskite film possessing larger grains, fewer pinholes, and reduced defects could be achieved. The inverted PSM with an active area of 61.56 cm 2 (10 × 10 cm 2 substrate) achieved a champion power conversion efficiency of 20.56% and significantly improved stability. This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.

The evolution of the contact scheme has driven the technology revolution of crystalline silicon (c-Si) solar cells. The state-of-the-art high-efficiency c-Si solar cells such as silicon heterojunction (SHJ) and tunnel oxide passivated contact (TOPCon) solar cells are featured with passivating contacts based on doped Si thin films, which induce parasitic optical absorption loss and require capital-intensive deposition processes involving flammable and toxic gasses. A promising solution to tackle this problem is to employ dopant-free passivating contact, involving the use of transparent and cost-effective wide band gap materials. In this review, we first introduce the dopant-free passivating contact, from carrier transport mechanisms, material classification to evaluation methods. Then we focus on the advances in different strategies to improve cell performance, including material property optimization, structural and interfacial engineering, as well as various post-treatments. At the end, the challenge and perspective of dopant-free passivating contact c-Si solar cells are discussed.

Bifacial perovskite (PVK)/crystalline silicon ( c ‐Si) tandem photovoltaic (PV) modules provide an effective strategy to further improve the efficiency and energy yield (EY) of c ‐Si PV modules. In this work, the energy outputs of bifacial tandem PV modules under outdoor conditions are analyzed by combining optical modeling, one‐diode equivalent circuit model, module tilt angle, and meteorological data, and a detailed comparative study with bifacial silicon heterojunction (SHJ) PV modules is also performed. The bifacial PVK/ c ‐Si tandem modules exhibit higher EY in locations with strong direct normal irradiance regardless of the ground type with any albedo, while bifacial SHJ modules exhibit similar or even higher EY than tandem modules in locations with strong diffuse horizontal irradiance (DHI) such as Chengdu. Considering factors such as EY and levelized cost of electricity, E g_PVK in the range of 1.58–1.62 eV is suitable for most application scenarios, while the deployment of bifacial SHJ PV modules is preferred in areas dominated by DHI, as represented by Chengdu. Herein, important implications for policy making in determining the cost‐effective type of PV modules are provided to generate renewable electricity.

Abstract As a promising candidate for high-density data storage and neuromorphic computing, cross-point memory arrays provide a platform to overcome the von-Neumann bottleneck and accelerate neural network computation. In order to suppress the sneak-path current problem that limits their scalability and read accuracy, a two-terminal selector can be integrated at each cross-point to form the one-selector-one-memristor (1S1R) stack. In this work, we demonstrate a CuAg alloy-based, thermally-stable and electroforming-free selector device with tunable threshold voltage and over 7 orders of magnitude ON/OFF ratio. A vertically-stacked 64 × 64 1S1R cross-point array is further implemented by integrating the selector with SiO2-based memristors. The 1S1R devices exhibit extremely low leakage currents and proper switching characteristics, which are suitable for both storage class memory and synaptic weight storage. Finally, a selector-based leaky-integrate-and-fire neuron is designed and experimentally implemented, which expands the application prospect of CuAg alloy selectors from synapses to neurons.