Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 22nd May 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 18, 2019
Previous Article Next Article

Amine additive reactions induced by the soft Lewis acidity of Pb2+ in halide perovskites. Part I: evidence for Pb–alkylamide formation

Author affiliations

Abstract

Metal halide perovskite materials (ABX3) employed in optoelectronic devices have rapidly achieved high efficiencies. Their performance can be partially attributed to intrinsic defects being electronically benign. Despite the inertness of defects within the bulk, such as ion vacancies, solution processing additives and surface passivation have been shown to enhance material properties. Thus, detailed knowledge of additive chemistry is desirous to elucidate passivation mechanisms and facilitate further improvements. In particular, the soft Lewis acid nature of Pb2+ has been overlooked heretofore as a key feature of amine-lead chemistry in perovskite preparations. In Part I of this study, we demonstrate that acid–base reactions between PbI2 and aliphatic amines yield alkylammonium and Pb–alkylamide species. The alkylammonium and alkylamide products are capable of occupying A-site cation and anion vacancies, respectively. Subsequent incorporation of these impurities at perovskite crystal surfaces or formation of non-perovskite phase inclusions likely influence the perovskite layer morphology and properties which are investigated in Part II. These results reveal a new mechanism by which optoelectronic properties of perovskites can be chemically modified. Additionally, the general concept of acidification of organic molecules solvated to Pb2+ promoting unexpected reactions is applied to explain amine reactions with other additives, such as formic acid. Understanding acid–base reactions induced by PbI2 complexing to protic molecules is useful to comprehend and predict defect/impurity chemistry in a wide variety of perovskite precursor formulations.

Graphical abstract: Amine additive reactions induced by the soft Lewis acidity of Pb2+ in halide perovskites. Part I: evidence for Pb–alkylamide formation

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Sep 2018, accepted on 15 Nov 2018 and first published on 15 Nov 2018


Article type: Paper
DOI: 10.1039/C8TC04871A
J. Mater. Chem. C, 2019,7, 5251-5259

  •   Request permissions

    Amine additive reactions induced by the soft Lewis acidity of Pb2+ in halide perovskites. Part I: evidence for Pb–alkylamide formation

    R. A. Kerner, T. H. Schloemer, P. Schulz, J. J. Berry, J. Schwartz, A. Sellinger and B. P. Rand, J. Mater. Chem. C, 2019, 7, 5251
    DOI: 10.1039/C8TC04871A

Search articles by author

Spotlight

Advertisements