Interfacial Engineering for Perovskite Photovoltaics: Multimolecular Synergy Versus All-In-One Integration

Abstract

Perovskite solar cells (PSCs) are promising next-generation photovoltaics, yet their efficiency promotion from lab-scale prototypes to industrial application is fundamentally hindered by interfacial instability and non-radiative recombination. These critical bottlenecks stem from complex defect chemistry, ion migration, energetic mismatches and material degradation at the perovskite heterojunction interface, which conventional empirical strategies often fail to address systematically. This perspective evaluates two pivotal paradigms for multidimensional top interfacial regulation: multimolecular synergistic systems, which utilize cooperative interactions among diverse functional additives, and all-in-one molecular integration, which employs sophisticated, multifunctional single molecules. We analyze how these distinct philosophies influence defect passivation kinetics, energy level alignment, operational resilience against ionic migration and environmental stressors. While multimolecular systems offer modular versatility, all-in-one integration provides superior structural precision to suppress phase separation and interfacial delamination. Furthermore, we assess their comparison and applicable scenarios. Finally, we propose a transition from empirical trial-and-error to data-driven predictive design. By establishing a unified molecular engineering framework, this paper provides a strategic roadmap for bridging the gap between research breakthroughs and reliable, commercially viable perovskite modules.