Annealing-Temperature-Dependent Formation of Formamidinium Lead Bromide Perovskite Thin Films for Light-Emitting Diode Applications

Younes, Saleh; Fallah Hamidabadi, Vahid; Bahari, Ali; Eftekharinia, Behroz; Silman, Hasans

doi:10.22075/ppam.2026.41678.1240

Annealing-Temperature-Dependent Formation of Formamidinium Lead Bromide Perovskite Thin Films for Light-Emitting Diode Applications

Document Type : Original Article

Authors

saleh younes ¹^{, 2}

Vahid Fallah Hamidabadi ¹^{, 3}

Ali Bahari ¹

Behroz Eftekharinia ⁴

hasans silman ⁵

¹ Department of Solid State Physics, University of Mazandaran, Babolsar 4741695447, Iran

² Department of Basic Sciences, Faculty of Cosmetology, Al Hawash Private University, Syria

³ Department of physics Education, Farhangian University, P.O.Box 14665-889,Tehran, Iran

⁴ Department of Physics, Faculty of Science, Babol Noshirvani University of Technology, Babol, 47148-71167, Iran

⁵ Department of Physics, Faculty of Basic Sciences, University of Tartous, Tartous, Syria

10.22075/ppam.2026.41678.1240

Abstract

Formamidinium lead bromide (FAPbBr₃) perovskite thin films are attractive emissive layers for green perovskite light-emitting diodes because of their narrow photoluminescence emission and favorable optoelectronic properties. In this study, FAPbBr₃ thin films were prepared through a two-step route combining thermal evaporation and solution processing. First, PbBr₂ layers were deposited by thermal evaporation, followed by spin coating of a formamidinium-based solution to promote the conversion of the precursor layer into FAPbBr₃. The resulting films were then thermally treated at different annealing temperatures ranging from 75 °C to 150 °C in order to evaluate the influence of post-deposition heating on film formation, morphology, crystallinity, optical response, and device performance. The results show that annealing temperature strongly affects the structural and optoelectronic quality of the perovskite layer. Among the investigated conditions, the film annealed at 125 °C exhibited favorable surface coverage and crystallographic characteristics and produced the best overall PeLED performance. The optimized PeLED device based on this film produced green emission with a peak wavelength of 531 nm and a full width at half maximum of 32 nm. A maximum luminance of 100 cd m⁻² and a current efficiency of 1 cd A⁻¹ were obtained. These findings indicate that careful control of the annealing step is an effective strategy for improving FAPbBr₃ thin-film quality and the performance of corresponding perovskite light-emitting diodes.

Keywords

Light Emitting Diodes

Formamidinium Lead Bromide

Perovskite Materials

Annealing process

Subjects

Methods of Deposition of Films and Coatings; Thin Film Growth and Epitaxy

© 2026 The Author(s). Progress in Physics of Applied Materials published by Semnan University Press. This is an open access article under the CC-BY 4.0 license. (https://creativecommons.org/licenses/by/4.0/)

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