Chen Weijie

Charge-engineered donor nanoparticles using doubly anionic surfactant SDP enhance electrostatic contrast, optimizing vertical morphology in thick films (300–400 nm). Water-based donor inks and non-halogenated processing enable eco-friendly fabrication. Devices achieve record efficiencies: 18.9% for binary (300 nm) and 20.3% for ternary systems, respectively, demonstrating unprecedented thickness tolerance and industrial potential.

Abstract

Aqueous processing represents a promising eco-friendly fabrication route for organic solar cells (OSCs), aligning with growing industrial sustainability requirements. While water-dispersed semiconducting nanoparticles (NPs) offer an attractive solution, the essential surfactants required for NP stabilization typically compromise device performance. In this study, surfactant-engineered donor NPs are systematically evaluated for constructing optimized active layers through a sequential layer-by-layer (LBL) deposition approach. The surfactant named sodium dodecyl phosphate (SDP), featuring dual anionic charges, generates exceptional electrostatic potential (ESP) differences that promote strong donor-acceptor interactions. This electrostatic engineering enables the formation of a pseudo-planar heterojunction structure (PPHJ) with ideal vertically graded morphologies in thick active layers. Therefore, the PM6:L8-BO binary OSC processed by mesostructured NP (mn)-LBL (SDP) strategy shows excellent thickness tolerance and achieved a PCE of 18.9% (certified as 18.3%) with a 300 nm active layer. Furthermore, the mn-LBL OSCs with the ternary PM6:L8-BO:BTP-eC9 deliver a champion PCE of 20.3% (certified as 19.9%) processed by a non-halogenated water/toluene solvent system. This work establishes a general surfactant selection paradigm that simultaneously addresses the conflicting demands of nanoparticle stabilization, morphological control, and device performance, paving the way for sustainable manufacturing of high-efficiency OSCs.

A mixed-halide perovskite film with initially homogeneous phase distribution is obtained by using 3-amino-5-fluorobenzamide additive, which selectively suppresses bromide precipitation during crystallization to mitigate halide phase segregation while demonstrating weak size dependence. The resulting 1.004-cm² perovskite/organic tandem solar cells achieved a remarkable 25.21% power conversion efficiency, coupled with impressive operational stability maintaining ≈90% initial performance over 1500 h.

Abstract

Mixed halide wide-bandgap (WBG) perovskites, used in high-performance perovskite/organic tandem solar cells (TSCs), are prone to phase segregation under light irradiation. Particularly, the initial inhomogeneous halide phase distribution in WBG perovskites can accelerate the phase segregation under operational stressors, thus hindering scaling of TSCs that require high phase homogeneity. Here, a selective delayed crystallization strategy is proposed in which a functional agent (3-amino-5-fluorobenzamide; AFBA) is used to regulate the initial halide phase distribution. The -NH₂ of AFBA, with a low electron-cloud density, shows a higher binding affinity with bromide than with iodide, thus selectively delaying the rapid crystallization of bromide; this phenomenon induces a homogeneous halide distribution across the film. The initial homogeneous film is phase-stable under operational stressors. As a result, the square-centimeter WBG perovskite front cell achieves a high efficiency of 18.61%. When stacked with organic subcells, the square-centimeter perovskite/organic TSC exhibits a remarkable efficiency of 25.21%, showing a weak-dependence of efficiency on size from 0.062 to 2.000 cm², as well as a prolonged operational lifetime with a T ₉₀ of 1500 h. Perovskite/organic TSCs are also connected in series with electrochromic devices to dynamically monitor the TSC performance via the color variation, providing insights for their future applications.

A novel SAM is designed by introducing heteroatoms into a spiro structure, named Spiro-S, which achieves four functions: 1) the spiro structure suppresses molecular aggregation to ensure uniform substrate coverage; 2) the incorporated heteroatoms passivate buried interface defects; 3) enhancing perovskite crystallization; 4) suitable energy level. The resulting Spiro-S-based device demonstrates an exceptional PCE of 25.75% with improved stability.

Abstract

In inverted perovskite solar cells (PSCs), the arrangement of self-assembled hole-transporting monolayers (SAMs) on substrates and their interaction with perovskite layer are critical for device efficiency and stability. Herein, two spiro SAMs are developed by introducing O and S atoms into the structure, named Spiro-O and Spiro-S, respectively. On one hand, the unique orthogonal molecular configuration of the spiro structure weakens intermolecular π–π interactions, thereby inhibiting molecular aggregation. This ensures uniform coverage on the substrate and a homogeneous surface potential distribution. On the other hand, the lone pair electrons of the introduced heteroatoms can interact with the Pb²⁺ ions, enhancing the quality of the perovskite film and effectively passivating the defects at the perovskite/SAM interface. The experimental and theoretical results show that the S in Spiro-S strongly interacts with perovskite, resulting in the formation of a more uniform and higher-quality crystalline perovskite layer. Compared to PSCs based on Spiro-O, the device with Spiro-S shows decreased defects at the buried interface, ultimately achieving an impressive power conversion efficiency of 25.75% (certified 25.19%). Furthermore, the PSCs based on Spiro-S also exhibit better long stability; the unencapsulated champion devices retain 92% of the initial efficiency after being stored at 25 °C for 1200 h.

5-hydroperoxy-1-methyl-2-pyrrolidinone (HMP) retards Rb⁺ reaction with the Pb-I framework, enabling Rb⁺ occupation at the A-site cation position. This allows Rb⁺ to alloy with formamidinium (FA), stabilizing the perovskite lattice and reducing strain. HMP boosts perovskite photovoltaic cell efficiency to a record 25.8% and enhances harsh-environment stability, offering a novel approach to regulate crystallization kinetics.

Abstract

Manipulating the kinetics of the reaction between A-site cations and Pb-I frameworks holds paramount importance for achieving high-quality, phase-homogeneous FA-dominant perovskites. It has been observed that when rubidium (Rb) serves as an A-site cation dopant, it tends to accumulate in the bulk region of the perovskite structure due to its pronounced affinity for Pb-I frameworks compared to FA⁺. Consequently, Rb⁺ ions struggle to alleviate the exaggerated tensile strain induced by the bulky FA cations on the perovskite surface. To mitigate this challenge, 5-hydroperoxy-1-methyl-2-pyrrolidinone (HMP) is introduced as an additive to invert the sequence between FA⁺ and Rb⁺ in reaction with the Pb-I frameworks. The introduction of HMP effectively stabilizes Rb⁺ cations within the perovskite lattice, leading to a surface enriched with Rb that exhibits diminished lattice strain and defects. Finally, a record power conversion efficiency (PCE) of 25.8% for 0.09 cm² perovskite solar cells and 19.8% for 52 cm² mini-module is achieved, which are fabricated via blade coating under ambient conditions with a relative humidity of ≤55%. Notably, these cells exhibit minimal hysteresis and demonstrate significantly enhanced resilience against illumination, dampness, and heat.

NiO _x suffers from high surface defects and an energy level mismatch with perovskite. Conventional organic modifiers, limited by weak binding, fail to deliver effective surface passivation and energy level regulation. We design [4-(trifluoromethyl)phenyl]triethoxysilane (3F-PTES), forming strong tridentate bonds with NiO _x to reduce surface defects, while its terminal dipole group optimizes energy alignment, enabling efficient p-i-n perovskite solar cells.

Abstract

Nickel oxide (NiO _x ) is a promising hole transport material for perovskite solar cells, but its high surface defect density and energy level mismatch with perovskite limit device efficiency. Conventional organic surface modifiers, relying on weak hydrogen bonds or single covalent bonds, fail to anchor stably to NiO _x , hindering their functional effectiveness. Here, A multidentate anchoring organic molecule, [4-(trifluoromethyl)phenyl]triethoxysilane (3F-PTES), is presented, forming robust tridentate covalent bonds with the NiO _x surface and significantly enhances interfacial binding strength and surface coverage compared with conventional groups (e.g., carboxyl). As a result, the interfacial defect density is reduced by 2.5-fold compared with carboxyl-modified counterparts and significantly suppresses the deprotonation reaction between NiO _x and perovskite, thereby greatly improving interfacial contact. The designed trifluoromethyl terminal group further enables precise tuning of NiO _x energy levels, achieving near-ideal band alignment with perovskite (energy offset ΔE = 0.01 eV). Incorporating this modified NiO _x into inverted devices, a champion power conversion efficiency (PCE) of 26.47% is achieved, along with outstanding operational stability, retaining 97% of their initial efficiency after 1500 h of continuous operation under maximum power point tracking (65 °C, 60% relative humidity, AM 1.5G illumination, ISOS-L-3 protocol).

This work reveals the mutual promotion of adjacent cation and anion vacancies in perovskite, and further develops a passivation strategy to synchronously passivate perovskite defects using a new additive of 2-hydrazinylpyrazine. The PSCs with active areas of 0.08 and 1 cm² achieve champion PCEs of 26.28% and 24.71%, retaining 93% efficiency after 1700 h under 1-sun illumination.

Abstract

The perovskite defect evolution directly impacts the efficiency and stability of perovskite solar cells (PSCs). In this work, the mutual promotion mechanism of adjacent cation and anion vacancies in perovskite is unveiled, which means the cation/anion vacancy induces the adjacent anion/cation vacancy through decreasing the formation energy. This mutual promotion mechanism provides an explanation for the dynamic evolution of defects, and emphasizes the necessity of simultaneously passivating of adjacent defects. Accordingly, a new additive of 2-hydrazinylpyrazine is utilized to passivate adjacent defects, considering its adjacent electron-rich N atom, which can chemically bond uncoordinated Pb, and the hydrazine group, which can anchor FA⁺ through hydrogen bonds. Besides, this 2-hydrazinylpyrazine also optimizes the perovskite crystallization through accelerating nucleation and slowing crystal growth, demonstrated by the in situ photoluminescence spectra. The resulting inverted 0.08 cm² and 1 cm² PSCs obtain PCEs of 26.28% and 24.71%, respectively. Moreover, the Target device shows enhanced stability by maintaining 93% and 90% of the initial efficiency after operating 1700 h under 1-sun illumination and being exposed to harsh thermal cycling for 150 times, respectively.

Nature Energy, Published online: 01 August 2025; doi:10.1038/s41560-025-01815-8

A dual optimization strategy for the perovskite/fullerene interface is developed through combining propanediamine iodine (PDAI₂)/isopropanol and PCBM/chlorobenzene solutions. The PDAI₂ in PCBM not only passivates perovskite surface defects but also induces n-type doping for PCBM. As a result, an efficiency of 21.84%, the highest value for inverted pure-iodide wide-bandgap perovskite solar cells is achieved.

Abstract

The excellent photostability of pure-iodide wide-bandgap (WBG) perovskite solar cells (PSCs) makes them ideal candidates for tandem and indoor photovoltaics. However, the efficiency is significantly restricted by interfacial charge transfer and recombination behaviors. Here, highly efficient pure-iodide WBG PSCs achieved through a dual optimization strategy for the perovskite/PCBM interface is presented. The PCBM/chlorobenzene solution, doped with propanediamine iodine (PDAI₂)/isopropanol solution, is deposited onto the Cs_0.4DMA_0.2FA_0.2MA_0.2PbI₃ perovskite layer. The presence of isopropanol notably improves the wetness of the PCBM solution, which is beneficial for depositing a smooth PCBM layer and economizing on the material. Most importantly, the PDAI₂ in PCBM not only passivates perovskite surface defects to suppress non-radiative recombination but also induces n-type doping for PCBM to enhance its carrier mobility and elevate the Fermi level with better energy level matching, thereby reducing energy loss and facilitating electron transfer. These benefits result in overall photovoltaic improvements, achieving a high efficiency of 21.84%, while retaining 92% of its initial efficiency after 1500 h of continuous illumination. Furthermore, when applied under indoor light illumination (1000 lux, 280 µW cm⁻²), the best cell demonstrates an impressive efficiency of 41.05%.

It is reported a quantum-well engineering breakthrough in 2D perovskites through dynamic phase-regulation of the fundamental Pb-I framework - a previously uncharted strategy to bridge the efficiency-stability divide. The resultant suppression of non-radiative recombination and enhanced charge transport culminates in a record 23.11% efficiency for GA(MA)₅Pb₅I₁₆-based 2D perovskite solar cell, which is the highest reported to date.

Abstract

Despite the enhanced environmental stability, 2D perovskites exhibit inferior optoelectronic performance compared to 3D counterparts, primarily due to voltage losses induced by phase dispersion and energy disorder. Here, a universal phase-regulation strategy is presented that directly targets the quantum-well-defining lead-iodide framework, bypassing conventional spacer-cation-based colloidal engineering. By incorporating a macrocyclic coordination molecule with dual functionality, dynamic coordination modulation and in situ lead immobilization are synchronously achieve: i) dynamic coordination and spatial confinement to guide colloidal self-assembly, enabling controlled quantum-well growth and nucleation via pre-ordering solvation intermediate phase, and ii) selective chelation of free Pb²⁺ ions through stable metal-organic bonds, mitigating lead leakage during processing and operation. Colloidal chemistry and crystallization dynamics analyses reveal that macrocyclic reduces n-phase polydispersity at the colloidal stage, yielding films with homogeneous phase distribution and minimized energy disorder. This optimizes carrier transport and suppresses energy loss, achieving a record power conversion efficiency of 23.11% for 2D perovskite solar cells. This work establishes a generalizable paradigm for phase regulation in low-dimensional perovskites, bridging the efficiency-stability gap by targeting the lead-iodide scaffold rather than peripheral components.

An effective interfacial passivation strategy is reported by introducing 1,2-bis(2-iodoethoxy)ethane as an interfacial passivator for inverted inorganic perovskite solar cells. The oxygen and iodide atoms from the passivator can coordinate with undercoordinated lead and occupy adjacent halide vacancies. Such dual interaction significantly enhances the device's photovoltaic performance and stability.

Abstract

Inorganic perovskite solar cells (PSCs) have attracted significant attention due to their excellent photothermal stability and potential for integration with silicon solar cells in tandem devices, offering great promise for future commercialization. However, the presence of numerous defects on the perovskite surface and poor energy level alignment between functional layers and perovskite in inverted PSCs result in power conversion efficiencies (PCE) that are still lower than those of conventional PSCs. Herein, an effective interfacial passivation strategy is proposed by introducing 1,2-bis(2-iodoethoxy)ethane (BIEE) molecules as an interfacial passivator for inverted PSCs. The oxygen atoms in BIEE can coordinate with undercoordinated lead ions, while iodide simultaneously occupies adjacent halide vacancies. This dual interaction effectively reduces defect density, suppresses ion migration, and improves energy level alignment at the interface. With this surface engineering approach, the inverted CsPbI_3−xBr_x PSCs achieved a PCE of 21.9% under 1-sun equivalent illumination and 42.6% under indoor light emiting diode (LED) lighting (1000 lux, 281 µW cm⁻²). Furthermore, under maximum power point (MPP) tracking with continuous one sun illumination for 1170 h in N₂ environment, the PCEs of the BIEE-modified device maintain 95.8% of the initial efficiency.

Surface chemical conversion of residual PbI₂ enables efficient and stable perovskite solar cells by 1,3-diphenyl-benzimidazolium iodide treatment: A nitrogen heterocyclic molecule is precisely synthesized as interfacial modifier to passivate defects, optimize the interface energy level, and construct robust 1D/3D perovskite structure, producing high-performance device with a high efficiency of 25.04%, additionally yielding 21.04% efficient module (total area of 36 cm²) with excellent operation and thermal stabilities.

Abstract

Perovskite films have long been plagued by defects, mainly located at grain boundaries, leading to device degradation, especially the effects of residual PbI₂. As effective grain boundary passivators, organic ammonium salts are thus extensively investigated. Here, the study introduces a nitrogen heterocyclic molecule, 1,3-diphenyl-benzimidazole iodide (DBI), for the post-treatment of the perovskite film to construct robust one-dimensional (1D)/three-dimensional (3D) perovskite structure. The 1D structure of DBPbI₃ formed from the interaction between residual PbI₂ and DBI enables the repair of local defects and enhancement of film stability. Concurrently, the double conjugated benzene and imidazole rings synergistically facilitate charge transfer and promote the optimization of energy levels, thereby boosting charge extraction. The corresponding 1D/3D perovskite solar cells (PSCs) yielded a high efficiency of 25.04% with excellent photo/thermal stabilities. The corresponding perovskite solar module exhibited an efficiency of 21.04% with a total area of 36 cm² with robust long-term stability.

A novel organic radical cation salt, XD1, is developed as a highly efficient p-type dopant for hole transport layers in perovskite solar cells (PSCs). With strong oxidative capability and excellent solubility, XD1 significantly enhances device performance. PSCs doped with XD1 achieve an outstanding power conversion efficiency (PCE) of 25.25% and demonstrate exceptional long-term stability.

Abstract

Chemical doping plays a crucial role in enhancing the charge transport and electrical conductivity of hole-transporting layers (HTLs) in perovskite solar cells (PSCs), leading to improved device performance and stability. However, developing highly soluble and oxidizing chemical dopants that ensure stable PSCs remains a significant challenge. Herein, the design and synthesis of a novel organic radical cation salt, XD1, comprising tris(4-methoxyphenyl)aminium as the radical cation and bis(trifluoromethane)sulfonimide (TFSI⁻) as the anion, are reported. XD1 exhibits excellent solubility in various organic solvents and demonstrates strong oxidative capability, significantly boosting the conductivity of HTLs by three orders of magnitude. Compared to conventional dopants like LiTFSI and Magic Blue (MB), XD1-doped Spiro-OMeTAD films demonstrate superior characteristics, including enhanced compactness, uniformity, and hydrophobicity. Remarkably, PSCs incorporating 2.0 mol% XD1 achieve a maximum power conversion efficiency (PCE) of 25.25%, surpassing the 24.44% PCE of LiTFSI-doped cells. Particularly, unencapsulated PSCs with XD1 retain over 91% of their initial efficiency after 1 000 h of continuous one-sun illumination at 85 °C in an N₂ atmosphere. This work represents a significant advancement in the development of highly soluble and efficient dopants for efficient and stable PSCs.

The residual PbI₂ was made to form stable metal-organic complexes at the grain boundaries by 2-iodoimidazole (2-IM). The inverted 1.66 eV PSCs achieved a PCE of 24.12%. This strategy has good universality and achieved an efficient 1.53 eV PSCs with a PCE of 26.84%. Inverted wide bandgap PSCs maintained 94% of their initial efficiency after continuous operation for 1000 hours at the maximum power point.

Abstract

The grain boundaries (GBs) instability induced by photodecomposition of residual PbI₂ is long-standing challenge for further simultaneous improvement of stability and power conversion efficiency (PCE) of perovskite solar cells (PSCs). Herein, a novel GB stabilization strategy through managing unstable residual PbI₂ within perovskite films is reported, which is realized by incorporating 2-iodoimidazole (2-IM) into perovskite precursor solution. The 2-IM can in situ convert unstable residual PbI₂ at GBs into robust metallo-organic complex 2-IMPbI₂ exhibiting an orderly hexagonal layered crystal structure. 2-IMPbI₂ is uncovered to have much better defect passivation effect and stability than PbI₂. The formed 2-IMPbI₂ facilitates perovskite crystallization, passivates GB defect, suppresses ion migration, mitigates phase segregation, and promotes carrier transport, contributing to simultaneously enhanced PCE and stability. Owing to the ingenious GB modulation strategy, the inverted 1.66 eV PSCs achieve a PCE of 24.12%, which is among the highest PCEs ever reported for 1.66 eV PSCs. This strategy demonstrates good universality by accomplishing efficient 1.53 eV PSCs with a PCE of 26.84%. Moreover, the inverted wide-bandgap PSCs with 2-IMPbI₂ maintain 94% and 90% of their initial efficiencies after 1000 h of continuous maximum power point operation and after 500 h of thermal stress at 85 °C, respectively.

Nature Communications, Published online: 30 July 2025; doi:10.1038/s41467-025-58980-3

Nature Communications, Published online: 31 July 2025; doi:10.1038/s41467-025-62392-8

Albendazole (ALB) post-treatment mitigated [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) aggregation and poor wettability, enhancing perovskite film crystallinity, optimizing energy-level alignment, reducing interfacial defects, and enhancing the carrier transport properties, resulting in a 1.67 eV inverted wide-bandgap perovskite solar cell with 22.68% power conversion efficiency (PCE) and achieving 29.06% efficiency in a four-terminal tandem with a CuInGaSe₂ (CIGS) subcell.

Abstract

Self-assembled materials (SAMs) like [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) are commonly used as hole transport layers (HTLs) in inverted wide-bandgap (WBG) perovskite solar cells. However, the poor wettability of perovskite precursor solutions on Me-4PACz and its polarity-induced aggregation hinder high-quality film formation. To address these challenges, albendazole (ALB) is introduced as a surface modifier for Me-4PACz. The ALB solution mitigates the aggregation of Me-4PACz and promotes the desorption and rearrangement process of weakly bound Me-4PACz molecules. Concurrently, its Lewis basic moiety improves film quality, reduces buried interfacial defects, and optimizes energy level alignment. Additionally, ALB forms directional π–π interactions with Me-4PACz, ultimately suppressing non-radiative recombination and facilitating charge carrier transport. As a result, ALB-optimized inverted WBG perovskite solar cells achieve a power conversion efficiency (PCE) of 22.68%, with unencapsulated devices retaining 93.87% of their initial efficiency after 736 h of continuous maximum power point tracking (MPPT) under illumination. Furthermore, integrating the ALB-modified semi-transparent perovskite top cell with a 1.03 eV bandgap CuInGaSe₂ (CIGS) bottom cell yields a four-terminal tandem device with an impressive total efficiency of 29.06%. This dual-objective strategy provides a simple and effective method for simultaneously improving the film quality of both the HTL and the perovskite layer.

Fluorene-functionalized spiro-phenothiazine (PTZ-Fl) exhibits strong Li⁺ affinity and thermal stability, enabling a PCE of 25.75% in small-area cells and 22.07% in 25 cm² modules. Under ISOS-L3 conditions, PTZ-Flbased devices retain over 80% efficiency after 1000 hours, demonstrating superior stability and scalability compared to spiro-OMeTAD for next-generation perovskite solar cells.

Abstract

Improving both the efficiency and long-term stability of perovskite solar cells (PSCs) is critical for their commercial deployment. Despite the widespread use of spiro-OMeTAD as a hole-transporting material (HTM), its inhomogeneous doping behavior and susceptibility to moisture and heat have hindered its large-scale industrial implementation. Here, a family of spiro-phenothiazine-based HTMs (PTZ) is reported to address these drawbacks. Among them, the fluorene derivative (PTZ-Fl) shows a larger Li⁺ affinity and forms a compact interphase by intercalation in the perovskite passivating layer that prevents Li⁺ migration. PSCs incorporating PTZ-Fl exhibit power conversion efficiencies (PCEs) up to 25.8% (certified 25.2% under reverse scan), retaining 80% of their initial performance after 1000 h under ISOS-L-3 protocol. Furthermore, a 5 × 5 cm mini-module reaches a PCE of 22.1%, surpassing spiro-OMeTAD-based PSCs and retaining over 85% of its efficiency after 1100 h under ISOS-D-1 protocol. These results demonstrate that PTZ-Fl not only enables high PCEs but also substantially improves operational stability, offering a promising pathway toward the large-scale deployment of next-generation PSCs.

A facile quasi-epitaxial growth strategy is innovatively developed to regulate tin-based perovskite crystallization kinetics by constructing two-dimensional growth template for reducing lattice orientational mismatch through energetically unfavorable pathway, yielding desirable facet orientation. Ultimately, the resulting device delivers the highest power conversion efficiency of 14.03% with outstanding reproducibility by two-step sequential deposition.

Abstract

Tin-based perovskite films typically exhibit random crystal orientations, with significant accumulation of defects acting as charge recombination centers, which severely limit device performance. Furthermore, the disordered two-dimensional (2D) perovskite significantly impacts the subsequent crystal growth of three-dimensional (3D) perovskite through epitaxial growth mechanism, while the insulating properties of bulky spacer cations impede out-of-plane charge transport. Herein, we have innovatively developed a facile quasi-epitaxial growth strategy by introducing 2-(naphthalen-2-yl)ethanamine hydroiodide (NEAI) with reinforced π-conjugation interaction to construct orientationally aligned 2D perovskite, which acts as a template for 3D perovskite with (100)-dominant facet orientation. NEAI reacts with SnI₂ to pre-form NEA₂SnI₄, which subsequently converts to NEA₂FASn₂I₇ and ultimately FASnI₃ through an energetically unfavorable pathway to delay crystallization kinetics. Moreover, this innovative approach optimizes carrier transport dynamics while conferring device robust thermal degradation resistance and enhanced long-term stability. Consequently, the NEAI-based solar cells exhibit the impressive efficiencies of 14.03% (0.04 cm²) and 12.44% (1 cm²), representing the record performance for two-step deposited tin-based perovskite photovoltaics. This study offers new insights into the preparation of highly ordered tin-based perovskite films, paving the way for high-performance lead-free perovskite photovoltaics.

Publication date: 17 September 2025

Source: Joule, Volume 9, Issue 9

Author(s): Duong Nguyen Minh, Md Azimul Haque, Fengjiu Yang, Steven P. Harvey, Ross A. Kerner, Chun-Sheng Jiang, Nikita S. Dutta, Steven Hayden, Margherita Taddei, Xinwen Zhang, Melissa A. Davis, Kelly Schutt, Joseph M. Luther

Strong dipole molecules are employed to regulate the monodispersity of self-assembled monolayer (SAM) micelles and coverage distribution of the resulting SAM films, achieving an efficiency of 26.58%.

Abstract

The application of self-assembled monolayers (SAMs) significantly drives the enhancement in the efficiency of perovskite solar cell (PSC). However, the transition mechanism of SAM molecules from colloidal solutions to films remains unclear. Herein, we systematically investigate the SAM precursor solutions and the crystallization quality of the resulting SAM and perovskite films. Fibrous micelles of about 460 nm are found in the pristine SAMs solution, leading to nonuniform and low coverage distribution of films. Strong dipole molecules are employed to establish supramolecular interactions with SAMs, enabling the formation of highly monodisperse cubic micelles in solution (160 nm) and uniform SAM films. The contact at buried interface is determined by the balance between dipole moment and steric hindrance. Consequently, the regulated SAMs based inverted PSCs (0.09 cm²) and mini-module (aperture area of 14.40 cm²) achieves efficiency of 26.58% (certificated 25.81%) and 22.95%, respectively. The optimized devices retain more than 96.30% of the initial efficiency for 5,100 h under the ISOS-D-1 condition with a linear fitting extrapolation to T₉₀ of 11,259 h and 98.30% efficiency for 2,660 h under the ISOS-L-2 condition. This work highlights the great potential of SAMs micelle regulation for achieving efficient and stable PSC.

Publication date: 17 September 2025

Source: Joule, Volume 9, Issue 9

Author(s): Abdulaziz S.R. Bati, Cheng Liu, Isaiah W. Gilley, Charles B. Musgrave, Aidan Maxwell, Julian A. Steele, Yi Yang, Hao Chen, Haoyue Wan, Jian Xu, Eduardo Solano, Rui Zhang, Chuying Huang, Benjamin Rehl, Nikolaos Lempesis, Virginia Carnevali, Andrea Vezzosi, Lewei Zeng, Luke Grater, Muzhi Li

Publication date: 20 August 2025

Source: Joule, Volume 9, Issue 8

Author(s): Hongjae Shim, Seongrok Seo, Charlie Chandler, Matthew K. Sharpe, Callum D. McAleese, Jihoo Lim, Beom-Soo Kim, Sajib Roy, Imalka Jayawardena, S. Ravi P. Silva, Mark A. Baker, Jan Seidel, Martin A. Green, Henry J. Snaith, Dohyung Kim, Jongsung Park, Jae Sung Yun

Publication date: 20 August 2025

Source: Joule, Volume 9, Issue 8

Author(s): Ke Wang, Zhiyuan Xu, Keqiang Li, Ru Li, Zhihao Guo, Yingguo Yang, Jiang Huang, Omar F. Mohammed, Zhigang Zang

In this study, a series of triphenylamine-based p-type conjugated polyelectrolytes (CPEs) is designed and synthesized, exhibiting long-range molecular ordering and compact laminar packing, which enables efficient hole transport and suppresses charge recombination. When employed as hole-transporting layer, TMPT-F:PMA delivered over 19% photovoltaic efficiency in rigid OSCs and demonstrated excellent mechanical durability in flexible devices.

Abstract

Hole-transporting layer (HTL) materials with a non-corrosive nature and good compatibility with flexible electrodes are highly desirable for advancing efficient and flexible organic solar cells (OSCs). Conjugated polyelectrolytes (CPEs) exhibit intriguing advantages as HTLs, such as tunable properties and excellent solution processability, but they suffer from poor charge-transporting properties, resulting in inferior performance to traditional HTLs. Herein, a series of pH-neutral CPEs are designed and synthesized that can form enhanced crystalline and highly ordered films. By tailoring trifluoromethyl substituents on the triphenylamine unit, TMPT-F exhibited exceptional long-range molecular ordering and compact laminar packing, along with a crystalline coherence length of 2.56 nm and a laminar packing distance of 1.48 nm, ultimately yielding an unprecedented conductivity of 3.3 × 10⁻² S m⁻¹ for the CPE-based HTL. The substantially enhanced charge-transporting property of the PMA-doped TMPT-F:PMA greatly suppressed the charge recombination in OSCs. The OSC modified by the TMPT-F:PMA HTL exhibited a PCE as high as 19.24%, which is superior to the PEDOT:PSS device. Moreover, TMPT-F:PMA showed excellent compatibility with flexible electrode, enabling a PCE of 16.52% for flexible OSC, and the device retained 83% of the initial PCE even after a 500-cycle bending at 5 mm radius.

Nature Materials, Published online: 18 July 2025; doi:10.1038/s41563-025-02305-8

Nature Photonics, Published online: 21 July 2025; doi:10.1038/s41566-025-01725-x

Nature Energy, Published online: 16 July 2025; doi:10.1038/s41560-025-01817-6