Key Takeaways & Executive Findings
- •• A self-buffered molecular migration strategy is developed to suppress spontaneous intermolecular exchange between perovskite intermediate phase and ambient moisture. • Exceptionally broad nucleation time and humidity tolerance windows are achieved for perovskite crystallization under ambient air conditions, with 1.68 eV-bandgap PSCs reaching a record efficiency of 22.09% at 50–60% relative humidity. • The strategy is broadly applicable to 1.53 eV- and 1.77 eV-bandgap perovskite films, enabling high-efficiency PSCs via air-based crystallization processing. • The n-i-p structured PSCs based on 1.53 eV- and 1.77 eV-bandgap perovskite films achieve outstanding reverse-scan PCEs of 25.23% and 19.09%, respectively, surpassing state-of-the-art ambient-air processed PSCs.
Abstract
Ambient-air, moisture-assisted annealing is widely used in fabricating perovskite solar cells (PSCs). However, the inherent sensitivity of perovskite intermediate-phase to moisture—due to fast and spontaneous intermolecular exchange reaction—requires strict control of ambient humidity and immediate thermal annealing treatment, raising manufacturing costs and causing fast nucleation of perovskite films. We report herein a self-buffered molecular migration strategy to slow down the intermolecular exchange reaction by introducing a n–butylammonium bromide shielding layer, which limits moisture diffusion into intermediate-phase film. This further endows the notably wide nucleation time and humidity windows for perovskite crystallization in ambient air. Consequently, the optimized 1.68 eV-bandgap n-i-p structured PSC reaches a record-high reverse-scan (RS) PCE of 22.09%. Furthermore, the versatility and applicability of as-proposed self-buffered molecular migration strategy are certified by employing various shielding materials and 1.53 eV-/1.77 eV-bandgap perovskite materials. The n-i-p structured PSCs based on 1.53 eV- and 1.77 eV-bandgap perovskite films achieve outstanding RS PCEs of 25.23% and 19.09%, respectively, both of which are beyond of the state-of-the-art ambient-air processed PSCs.
1. Introduction
Significant advancements in the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) have garnered substantial research interest in the field of photovoltaic technologies [1]. The PCE has risen from 3.81% in 2009 to a certified value of 26.7% in 2024 [1, 2]. In addition, the low-cost and abundant raw materials, relatively modest purity requirements, and simple solution-processing methods make PSCs a promising alternative to silicon-based solar cells in terms of cost-effectiveness [3, 4]. It is widely acknowledged that achieving high-performance PSCs requires the growth of high-quality, stable, and uniform perovskite films [2, 5, 6]. Numerous studies have shown that both the growth dynamics and stability of perovskite films are highly sensitive to environmental factors, particularly moisture [7–9]. Moisture can disrupt the organic–inorganic interactions within the perovskite materials, leading to their degradation into PbI2 [10, 11]. In this case, the preparation of perovskite films requires precise control of the surrounding atmosphere, and hence, many high-efficiency devices can only be fabricated in nitrogen-filled gloveboxes, which, unfortunately, increases production costs [12–14].
With increasing efforts to develop high-performance PSCs in ambient air, it has been found that the controlled moisture levels can improve film morphology and crystallinity, but these effects are largely valid during the ambient-air annealing stage [15–18]. For example, Yang et al. [19] reported for the first time a growth mode via thermal annealing of the perovskite intermediate-phase film in a humid environment (e.g., ambient air) to greatly improve the film quality, grain size, carrier mobility, and lifetime. And, they proposed that when annealed in the air, highly hygroscopic methylammonium (MA) cations pull moisture from the environment and then lead to the partial dissolution of the perovskite grains, finally enlarging their sizes [20]. Huang et al. [21] used in situ grazing-incident wide-angle X-ray scattering (GIWAXS) to capture the phase transformation of perovskite films during annealing under different relative humidity (RH) conditions, from which they reckoned that a moderate water content accelerates the crystal formation and enhances the texture orientation of the films. Liu et al. [8] designed air exposure-free characterization techniques to demonstrate that a controllable moisture treatment for perovskite intermediate-phase can promote the mass transportation of organic salts, and translates to high-quality perovskites with much-suppressed defects. Zhong et al. [9] showed that ambient air processing can be optimized to achieve high-quality films.
Loading authentic research manuscript (Pages 1–5)...
Mei Yang, Weidong Zhu, Laijun Liang, Wenming Chai, Xiaomeng Wu, Zeyang Ren, Long Zhou, Dazheng Chen, He Xi, Chunfu Zhang, Jincheng Zhang, Yue Hao (2026). Moisture-Resistant Scalable Ambient-Air Crystallization of Perovskite Films via Self-Buffered Molecular Migration Strategy. Nano-Micro Letters. https://doi.org/10.1007/s40820-025-01851-9
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the main challenge in ambient-air processing of perovskite solar cells?
The main challenge is the inherent sensitivity of the perovskite intermediate phase to moisture, which causes fast and spontaneous intermolecular exchange reactions, requiring strict humidity control and immediate thermal annealing, thereby increasing manufacturing costs and leading to fast nucleation.
How does the self-buffered molecular migration strategy work?
The strategy introduces a n-butylammonium bromide shielding layer that limits moisture diffusion into the intermediate-phase film, thereby slowing down the intermolecular exchange reaction and widening the nucleation time and humidity windows for perovskite crystallization in ambient air.
What efficiency was achieved with the optimized 1.68 eV-bandgap perovskite solar cell?
The optimized 1.68 eV-bandgap n-i-p structured perovskite solar cell reached a record-high reverse-scan power conversion efficiency of 22.09% when processed in 50–60% relative humidity.
Is the strategy applicable to other bandgap perovskite materials?
Yes, the strategy is broadly applicable to 1.53 eV- and 1.77 eV-bandgap perovskite films, achieving outstanding reverse-scan PCEs of 25.23% and 19.09%, respectively, which surpass state-of-the-art ambient-air processed PSCs.
What are the key advantages of this strategy for manufacturing?
The strategy enables scalable ambient-air crystallization of perovskite films with wide humidity tolerance, reducing the need for strict environmental control and immediate annealing, thus lowering production costs and facilitating large-scale manufacturing.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.