Enhancing and Extinguishing the Different Emission Features of 2D (EA 1− x FA x ) 4 Pb 3 Br 10 Perovskite Films

TitleEnhancing and Extinguishing the Different Emission Features of 2D (EA 1− x FA x ) 4 Pb 3 Br 10 Perovskite Films
Publication TypeJournal Article
Year of Publication2022
AuthorsKennard, Rhiannon M., Clayton J. Dahlman, Emily E. Morgan, Juil Chung, Benjamin L. Cotts, Joseph R. A. Kincaid, Ryan A. DeCrescent, Kevin H. Stone, Shobhana Panuganti, Yahya Mohtashami, Lingling Mao, Richard D. Schaller, Alberto Salleo, Mercouri G. Kanatzidis, Jon A. Schuller, Ram Seshadri, and Michael L. Chabinyc
JournalAdvanced optical materials
Date Published06/2022

Two-Dimensional (2D) hybrid perovskites are attractive for thin-film optoelectronic devices. However, in thin films,the color of optical emission and the texture of crystalline domains are often difficult to control. Here, a method for extinguishing or enhancing different emission features is demonstrated for the family of 2D Ruddlesden-Popper perovskites (EA1−xFAx)4Pb3Br10(EA = ethylammonium, FA = formamidinium).When grown fromaqueous hydrobromic acid, crystals of(EA1−xFAx)4Pb3Br10retain all the emission features of their parent compound,(EA)4Pb3Br10. Surprisingly,when grown from dimethylformamide (DMF), an emission feature, likely a p-like, self-trapped exciton, near 2.7 eV is missing. Extinction of this feature is correlated with DMF being incorporated between the 2D Pb-Br sheets, forming (EA1−xFAx)4Pb3Br10∙(DMF)y. Without FA, films grown from DMF form (EA)4Pb3Br10, retain little solvent,and have strong emission near 2.7 eV. Separately, slowing the kinetics of film growth strengthens a different emission feature, likely a different type of self-trapped exciton, which is much broader and present in all compositions. Films of (EA1−xFAx)4Pb3Br10∙(DMF)y have large, micron-sized domains and homogeneous orientation of the semiconducting sheets, resulting in low electronic disorder near the absorption edge. The ability to selectively strengthen or extinguish different emission features in films of (EA1−xFAx)4Pb3Br10∙(DMF)y reveals a novel way to tune the emission color in these compounds.