Beyond the Surface: Three-Dimensional Distribution and Defect Passivation of Self-Assembled Monolayers in Perovskite Solar Cells
Year: 2026
Type: article
Abstract: Self-assembled monolayers (SAMs) are widely employed to tune interfacial properties in perovskite solar cells (PSCs), yet they have so far been regarded as strictly two-dimensional surface modifiers. Here, we uncover the three-dimensional (3D) nature of perfluorinated silanol-based SAMs applied onto perovskite films and their impact on both the photovoltaic performance and stability of PSCs. Using high-resolution 3D nanoscale secondary ion mass spectrometry, which directly maps their lateral and vertical distribution, we reveal that these SAMs not only decorate the perovskite surface but also selectively penetrate and anchor at grain-boundary iodine-deficient regions within ∼100 nm of the film. This dual surface-bulk passivation reshapes the defect landscape in perovskite thin films, yielding reduced nonradiative recombination, more favorable interfacial energetics, enhanced photovoltaic performance, and increased environmental stability. Our findings reposition SAMs as volumetric chemical modifiers rather than merely interface dipole layers, highlighting their potential for molecular-level engineering in perovskite optoelectronics.
Source: ACS Nano
Institutions: Centre National de la Recherche Scientifique, Université Paris Sciences et Lettres, Sorbonne Université, Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris, Muséum national d'Histoire naturelle, Institut de minéralogie, de physique des matériaux et de cosmochimie, Institut de Recherche pour le Développement, Chimie ParisTech - PSL, Institut de Recherche de Chimie Paris, Université Paris-Saclay, Laboratoire de Génie Électrique et Électronique de Paris, CentraleSupélec, Soochow University, Macau University of Science and Technology, Université Paris Cité, Interfaces Traitements Organisation et Dynamique des Systèmes
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Awards: G1023385468, G2787848433, Unlocking the Bottlenecks for Solution-Processed Narrow Bandgap Solar Cells with Less or No Lead, G470805120, Multimodal approach combining IN-situ, ex-situ and Operando CharacTerizAtion with SimUlations for Highly REliable Next Generation Photovoltaics, G9000241637
OpenAlex ID: W7144032549