Halide Exchange via Perovskite Nanocrystals for Interfacial Defect Passivation in Solar Cells
Year: 2026
Type: preprint
Abstract: Metal halide perovskites have emerged as leading candidates for next-generation optoelectronics, with perovskite solar cells (PSCs) achieving power conversion efficiencies (PCEs) exceeding 26%. However, solution-processed hybrid perovskite films typically suffer from non-radiative recombination and ion migration driven by surface and interfacial defects, limiting device performance, fill factor, and long-term stability. To address these bottlenecks, we report a novel, scalable interface engineering strategy utilizing bromide-rich perovskite nanocrystals to modify 3D perovskite film surfaces via self-driven solid-state halide exchange. The resulting surface-graded heterojunction passivates key iodide vacancies, suppresses ion migration, and optimizes charge extraction. Consequently, modified PSCs demonstrate a ~5% boost in short-circuit current density () and an improved fill factor of 75.3%, driving a ~10% relative increase in PCE from 20.13% (control) to 22.19%. This simple, single-step nanocrystal treatment provides a promising pathway toward robust, scalable, and high-efficiency optoelectronic architectures.
Source: ChemRxiv
Institution: Indian Institute of Science Bangalore
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221748108