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Wang et al. Energy Mater. 2026, 6, 600064 Page 13 of 34

This review has highlighted the multifaceted nature of structural defects in perovskite materials and the
diverse range of additive engineering strategies developed to passivate them across atomic, mesoscopic, and
macroscopic length scales. Defect-selective additive engineering strategies and key functional groups for
perovskite passivation are summarized in Table 1. From mitigating anion vacancies through transient Cl -
donors to suppressing antisite defects via multidentate ligands and healing grain boundaries through
environmental treatments, additive engineering has proven essential for enhancing carrier dynamics,
including prolonged carrier lifetimes, improved charge mobilities, and reduced non-radiative recombination
losses. However, the vast chemical space of potential additives, encompassing organic cations, anions,
polymers, and hybrid molecules, poses a combinatorial challenge that cannot be efficiently addressed by
traditional trial-and-error approaches. Each additive interacts with multiple defect types through complex
mechanisms (coordination, hydrogen bonding, electrostatic interaction), and their effects are highly sensitive
to processing conditions. This complexity calls for a paradigm shift from empirical screening to rational,
data-driven design. Herein lies the transformative potential of ML. By integrating high-throughput
experimental data, computational simulations (e.g., density functional theory (DFT)), and structural
descriptors, ML models can predict the defect-passivation efficacy of novel additives, identify synergistic
combinations, and optimize processing parameters [129] . For instance, ML can correlate molecular features
(e.g., electronegativity, steric effects) with passivation performance, enabling the discovery of next-generation
multifunctional additives [131] . The convergence of additive engineering and ML thus represents a powerful
pathway toward accelerated materials discovery, enhanced reproducibility, and ultimately, the
commercialization of high-performance PSCs.

Interface engineering for enhanced stability
In high-performance PSCs, the top and buried interfaces serve as the primary conduits for charge extraction
but simultaneously represent the most vulnerable frontiers for chemical degradation and structural
deterioration. While the preceding sections primarily emphasized how targeted additive engineering
passivates localized interfacial defects to suppress non-radiative recombination, the ultimate significance of
interfacial management extends far beyond initial efficiency enhancements. By integrating these multifaceted
chemical and mechanical modifications, interface engineering collectively endows devices with the
exceptional operational stability required to withstand prolonged exposure to severe thermal, photonic, and
environmental stressors.

Functional group bonding
To reinforce the physicochemical shield at these vulnerable boundaries, the advanced interfacial strategies
previously discussed for defect passivation, including self-assembled monolayer (SAM), co-assembled
surface modifiers, and vertical molecular bridges, are equally applicable and highly effective for broader
stability enhancement. The fundamental logic remains consistent across these scales. Whether the objective
is passivating localized interfacial imperfections or achieving comprehensive macroscopic interface
engineering, establishing strong chemical interactions between the perovskite absorber and the charge
transport materials is essential. Echoing the dual functional nature of the previously discussed TDCA
bridging strategy, Xiong et al. [132] demonstrated that perfluorophenylacylamide (PFPA) effectively
coordinates with Pb through its carbonyl group and leverages strong dipole interactions to fine-tune the
2+
energy band alignment, thereby maintaining over 85% of its initial efficiency after 350 h of storage under
ambient air at room temperature and 45% relative humidity. Further extending this bridging paradigm to the
top electron extraction interface, Hu et al. designed the multifunctional 3-aminomethyl-benzothiophene
[133]
(3-AMBTh) to act as an efficient charge bridge. Within this architecture, the amine group selectively reacts
with V to heal the perovskite surface, while its aromatic backbone engages in robust π-π stacking with
I
fullerene-based electron transport layers (ETLs). This dual-action bridge effectively suppresses charge
recombination and substantially extends the operational lifetime of the device, enabling it to retain > 94% of

its initial efficiency after 1,000 h of storage.