Organic-inorganic hybrid perovskite solar cells (PSCs) have emerged as a leading photovoltaic technology driven by their high power conversion efficiencies (PCEs), low production costs, and facile fabrication processes
[1−4]. Since their initial report in 2009, the PCE of PSCs has surged from 3.8% to over 26%, now rivaling and, in some cases, surpassing conventional photovoltaic technologies
[5]. This breakthrough is mainly attributed to the excellent optoelectronic properties of halide perovskites, including high absorption coefficient, low exciton binding energy, long carrier diffusion length, tunable bandgap, and high carrier mobility
[6−12]. Despite these advantages, the commercialization of PSCs is hindered by the inherent instability of the materials. The soft, ionic lattice inevitably facilitates the formation of structural defects, particularly at the surface and grain boundaries (GBs) of polycrystalline films. These defect sites act as non-radiative recombination centers, leading to open-circuit voltage losses and accelerating the degradation of device efficiency and long-term operational stability
[13−15]. Consequently, defect passivation has become the crucial strategy for suppressing recombination losses and inhibiting ion migration, which is essential for enhancing PSC efficiency and stability.
To address this challenge, extensive research has been conducted on various chemical passivation materials, including small molecules
[16−18], polymers
[19−20], ionic liquids
[21−22], and inorganic salts. Among these, Lewis base small molecules (e.g., phosphine oxides, thiophenes) have received considerable attention due to their effective passivating properties
[23−25]. As electron donors, Lewis base small molecules can coordinate with undercoordinated Pb
2+ ions at perovskite grain boundaries or surfaces, forming stable Pb−O/Pb−N bonds. This interaction suppresses deep-level trap states, reduces non-radiative recombination, and enhances film morphology by promoting uniform nucleation during crystallization. Therefore, Lewis base small molecules can significantly improve the overall performance of the device. Their molecular tunability, solution-processability, and applicability across various device architectures further underscore their potential for broad implementation. However, the discovery and optimization of high-performance Lewis base passivators remain largely empirical, relying on intuition-driven screening that lacks a fundamental understanding of the underlying structure-property-performance relationships. Moreover, due to the vast molecular design space, this trial-and-error approach is inherently inefficient
[26]. Therefore, establishing rational design principles is urgent to rapidly and accurately guide the identification and development of novel, efficient passivation materials, thereby accelerating the advancement of perovskite photovoltaic technologies.
To overcome this inherent limitation, machine learning (ML) has recently emerged as a transformative tool in perovskite material design and device performance optimization, leveraging its powerful data mining and predictive capabilities
[27−29]. Previous ML applications in PSCs include identifying key molecular descriptors correlated with efficiency in ammonium salts
[30], systematically evaluating organic halide salts for improved stability
[31], and integrating drift-diffusion physical modeling to select optimal passivators
[32]. However, ML research specifically focused on Lewis base passivators is still in its early stages. Currently, there is a lack of dedicated feature descriptor libraries tailored for Lewis base molecules in PSCs, as well as benchmark datasets that systematically correlate molecular features with device performance metrics such as PCE enhancement. As a result, existing studies are largely confined to performance validation of individual molecules, leading to fragmented research without generalizable design principles or systematic screening strategies. This severely hinders the rational design and rapid discovery of high-performance Lewis base passivators.
In this work, we proposed an intelligent screening framework based on data-driven ML to rationally identify high-performance Lewis base additives. A dataset for machine learning training was constructed by collecting 146 experimental data points from the literature. Six binary classification prediction models were constructed using six ensemble learning algorithms—including Random Forest (RF), Extreme Gradient Boosting (XGBoost), Gradient Boosting Decision Tree (GBDT), Light Gradient Boosting Machine (LightGBM), Categorical Boosting (CatBoost), and Adaptive Boosting (AdaBoost)—with a threshold of PCE improvement rate ≥2%. The results show that the LightGBM model exhibited superior predictive accuracy, and subsequent Shapley Additive Explanations (SHAP) analysis revealed key molecular descriptors that governed passivation efficacy, providing in-depth mechanistic analysis and guidance for the screening and design of superior Lewis base passivators. The predictions of the LightGBM model were verified through the binding energy and defect formation energy calculated using the density functional theory (DFT) method. Moreover, the model’s predictions were further validated by applying three novel, model-identified additives in device fabrication. The champion additive, (S)-pyrrolidine-3-carboxylic acid ((S)-PCA), yields a certified PCE of 24.05%. This work highlights the immense potential of machine learning in accelerating the identification of excellent Lewis base additives for PSCs, which opens a new avenue for developing more efficient perovskite devices.