In the relentless pursuit of renewable energy technologies, perovskite solar cells (PSCs) have emerged as a transformative force poised to rival traditional silicon-based photovoltaics. Recent advancements in metal halide perovskites have catalyzed a dramatic leap in power conversion efficiencies, now approaching the benchmark set by commercial silicon solar cells. This breakthrough heralds a new era in photovoltaic innovation, with the industrialization of PSCs more attainable than ever. Researchers have long sought to overcome persistent challenges in optimizing the interface and charge transport layers of PSCs, which have limited scalability and performance. A pioneering study by Liang, Chen, Wang, and colleagues presents a revolutionary “SAM-in-matrix” strategy that promises to surmount these hurdles and unlock unprecedented device efficiencies and stability.
At the heart of PSC performance improvement lies the engineering of the hole transport layer (HTL), a crucial component responsible for facilitating efficient charge extraction and minimizing energy losses. High-efficiency inverted PSCs have adopted self-assembled molecules (SAMs) as HTLs due to their ability to form well-ordered monolayers, enhancing interfacial contact and charge transport. However, SAMs suffer intrinsic drawbacks including molecular aggregation and hydrophobic surfaces, which induce nanoscale voids and impede uniform perovskite film growth. This aggregation compromises the electrical conductivity and long-term stability of the device, presenting formidable barriers to large-area device fabrication and commercial viability.
To overcome these intrinsic limitations, the research team deployed a novel approach by embedding partial SAM molecules within a chemically stable matrix composed of tris(pentafluorophenyl)borane. This “SAM-in-matrix” design ingeniously disrupts the molecular stacking that typically leads to aggregation, enabling the dispersion of SAMs in a controlled manner throughout the matrix. By fine-tuning the distribution and interaction of these molecules, the researchers have forged efficient charge transport channels in the HTL, substantially enhancing the interfacial electronic properties. This innovation not only mitigates the formation of nanovoids but also significantly improves overall film uniformity and stability.
The mechanistic insights into this novel HTL architecture were elucidated through rigorous 2D lattice Monte Carlo simulations, complemented by experimental validation. These simulations captured the stochastic behavior of SAM distribution within the matrix and predicted optimal configurations for minimized aggregation and maximized conductivity. Experimentally, devices fabricated with the SAM-in-matrix HTL exhibited compact surface coverage and improved conductivity relative to traditional SAM-only films. The synergistic effect of the matrix embedding enhanced the electrical pathways available for hole transport and suppressed recombination losses at the interface between the perovskite absorber and the HTL.
Uniquely, the universality of this SAM-in-matrix strategy was demonstrated by applying it to various commonly used SAM molecules, with each variant yielding a consistent boost in device efficiency. This universal applicability underscores the robustness and flexibility of the method, making it a viable platform for diverse molecular systems and scalable fabrication processes. The compact grain formation and reduced buried nanovoids facilitated by the matrix substantially improve device reproducibility, a critical metric for commercial adoption.
The industrial implications of this research are profound, notably for scalable manufacturing of PSCs on flexible and rigid substrates alike. By integrating the SAM-in-matrix HTL on fluorine-doped tin oxide (FTO)/nickel oxide (NiOx) substrates, the authors achieved not only improved NiOx conductivity but also larger, high-crystallinity perovskite grains. This dual enhancement enables the fabrication of large-area perovskite films with superior optoelectronic quality, overcoming one of the most challenging obstacles in perovskite module manufacturing: the transition from lab-scale devices to industrial-scale production.
Building upon these advances, the research culminated in the creation of a 1 meter by 2 meter perovskite solar module, a size scale highly relevant for commercial applications. Most notably, this module achieved a certified power conversion efficiency of 20.05%, setting a new record for large-area perovskite photovoltaics. This milestone not only validates the practical potential of the SAM-in-matrix approach but also signifies a compelling stride toward the commercialization of perovskite solar technology.
The stability and durability of photovoltaic modules remain paramount for real-world use, and the SAM-in-matrix HTL contributes positively to these aspects. The matrix’s molecular confinement inhibits deleterious phase segregation, a pervasive problem that plagues traditional organic HTLs under thermal and operational stress. Enhanced encapsulation within the matrix leads to improved resistance against moisture ingress and photodegradation, critical factors determining module lifespan and reliability.
Further exploration investigated the interfacial energetics imparted by the matrix-confined SAM layers, revealing optimized band alignments that facilitate hole extraction while suppressing non-radiative recombination pathways. The ability to tune interfacial energetics through matrix composition and SAM selection offers a powerful tool for tailoring device performance on a molecular level, a nuanced control mechanism seldom achievable in conventional PSC architectures.
The multidisciplinary methodology combining computational modeling with meticulous experimental characterization exemplifies a new paradigm in materials innovation. By leveraging Monte Carlo simulations to guide molecular design and interfacial engineering, the study sets a precedent for data-driven optimization of complex molecular systems. This integrative strategy accelerates discovery and enhances the reproducibility of PSC component fabrication.
Looking forward, the implications of this research extend beyond photovoltaics, potentially influencing a broader array of optoelectronic devices such as light-emitting diodes, photodetectors, and field-effect transistors, where interface engineering is critically linked to device efficiency and stability. The concept of confining functional molecules within stable matrices may inspire novel material platforms for advanced electronics and energy technologies.
In conclusion, the groundbreaking “SAM-in-matrix” strategy introduced by Liang and colleagues represents a pivotal advancement in perovskite solar technology. By resolving fundamental issues related to molecular aggregation, conductivity, and scalability, this approach paves the way for high-performance, stable, and manufacturable perovskite photovoltaic modules. As this technology continues to mature, it promises to accelerate the deployment of cost-effective and efficient solar energy solutions on a global scale, contributing significantly to the sustainable energy landscape.
Subject of Research: Perovskite photovoltaics, hole transport layers, molecular interface engineering
Article Title: A matrix-confined molecular layer for perovskite photovoltaic modules
Article References:
Liang, Y., Chen, G., Wang, Y. et al. A matrix-confined molecular layer for perovskite photovoltaic modules. Nature (2025). https://doi.org/10.1038/s41586-025-09785-3
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