Turkish Journal of Chemistry
Abstract
A multiscale computational investigation integrating density functional theory (DFT) and molecular dynamics (MD) simulations was conducted to elucidate the mechanisms through which sulfur-containing donor molecules stabilize the photoactive α-phase of formamidinium lead iodide (FAPbI3) perovskites. The binding energetics, charge-transfer behavior, and hydrogen-bonding interactions of thiourea (TU), thiosemicarbazide (TSC), thiocyanate (SCN–), and diethyldithiocarbamate (DTC) were systematically analyzed. DFT results revealed pronounced Pb–S coordination and multidentate hydrogenbonding, with binding energies following the trend SCN–>TSC>DTC>TU. Thermodynamic analysis demonstrated that these additives lower the Gibbs free energy difference, thereby stabilizing the black α-phase, with TSC, TU, and to a lesser extent DTC exhibitingthe most pronounced effects. Projected density of statesanalysis confirmed that TU and DTC effectively suppressed trap states near the band edges without introducing midgap defects. MD simulations demonstrated preferential adsorption of all S-donors on FAPbI3 (001) surfaces, forming three to four hydrogen bonds per frame and achieving adsorption energies up to −52 kJ∙mol-1. These findings reveal a direct correlation between coordination strength, electronic coupling, and thermodynamic stabilization, establishing TU, TSC, and DTC as promising additives for improving the phase stability and electronic performance of FAPbI3-based perovskite solar cells.
Author ORCID Identifier
ILNAR NURGALIEV: 0000-0002-6983-4375
AKBARXON HAMZAYEV: 0000-0002-6808-615X
MURAD MARASULOV: 0000-0003-1950-5634
ZAVKIDDIN JULLIEV: 0009-0007-6873-5811
AKHMAD OBLAKULOV: 0009-0005-2844-8354
NIGMAT ASHUROV: 0000-0003-0765-5942
DOI
10.55730/1300-0527.3779
Keywords
FAPbI3 perovskites, additives, phase stabilization, surface passivation, density functional theory, molecular dynamicssimulations
First Page
49
Last Page
60
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
NURGALIEV, I, HAMZAYEV, A, MARASULOV, M, JULLIEV, Z, OBLAKULOV, A, & ASHUROV, N (2026). Comparative computational study of sulfur-donor additives for stabilization of FAPbI3 perovskites. Turkish Journal of Chemistry 50 (1): 49-60. https://doi.org/10.55730/1300-0527.3779
