Abstract. Metal-halide perovskite solar cells (PSCs) combine excellent optoelectronic properties with low-temperature processing, but their operational stability is strongly affected by ionic migration, defect-assisted recombination, and thermo-mechanical stress. Here, we develop a multiscale computational framework linking molecular passivation by 1,3-bis(4-methoxyphenyl) thiourea (BPT) with ionic, electronic, thermal, and mechanical behavior in a mixed-cation/mixed-halide perovskite solar cell. Density functional theory calculations show that BPT increases the migration barriers from 0.58 to 0.75 eV for iodide, from 0.81 to 0.95 eV for FA⁺, and from 0.69 to 0.85 eV for MA⁺. These parameters were incorporated into a coupled COMSOL Multiphysics model. BPT passivation suppresses iodine-vacancy-related states, increases the simulated PCE from 20.9% to 22.6% reduces the maximum temperature rise from 7.4 to 4.8 K, and decreases the maximum von Mises stress from 27.3 to 21.5 MPa. The framework provides a mechanistic connection between molecular passivation and device-scale stability.
Key words. perovskite solar cells; BPT; ion migration; DFT; COMSOL Multiphysics; passivation.
DOI: 10.66640/UJP-2026-5-00017
Citation: Ilnar N. Nurgaliev, Murad B. Marasulov, Ulugbek B. Eliyev, Akbarhon I. Hamzayev, Nigmat R. Ashurov, A MULTISCALE COMPUTATIONAL FRAMEWORK FOR PREDICTING PASSIVATOR PERFORMANCE IN PEROVSKITE SOLAR CELLS: COUPLING DFT MIGRATION BARRIERS WITH COMSOL DEVICE SIMULATIONS. Uzbekistan Journal of Polymers, Vol. 5(3) 2026: pp.45-54. DOI: 10.66640/UJP-2026-5-00017