Issue 9, 2024

Stability of CsPbI3 with divalent cations incorporated via mechanochemical alloying

Abstract

Cubic CsPbI3 is a promising perovskite material for optoelectronic applications. This material possesses an energy band gap of 1.7 eV and an optical absorption coefficient of 105 cm−1, and can be synthesized at high temperatures using various methods. However, cubic CsPbI3 faces a significant challenge with degradation reported under ambient conditions. This degradation results in the formation of a delta phase, which comprises a non-perovskite structure with poor optical and electrical properties at room temperature. This paper proposes the partial substitution of lead in CsPbI3 with divalent cations, such as Sn2+, Mn2+, Ni2+, and Ca2+, to improve the overall stability. These cations were selected because their ionic radii meet the Goldschmidt factor and favor the formation of cubic halide perovskites. For the synthesis of the materials, a solid-state mechanochemical method is used that allows for the incorporation of the above-mentioned cations into the CsPbI3 matrix in a single step at room temperature. Replacing Pb2+ with Sn2+ produced the most stable material and resulted in a cubic perovskite structure with similar optical properties to CsPbI3. In particular, a composition of CsPb0.6Sn0.4I3 resulted in cubic perovskite and did not show degradation when exposed to room temperature, ambient humidity, and atmospheric pressure for up to 25 days. On the other hand, even though Ca2+ possesses a smaller ionic radius than Pb2+, replacing Pb2+ with Ca2+ was not effective in stabilizing CsPbI3 due to the hygroscopic nature of CaI2. Replacing Pb2+ with Mn2+ and Ni2+ produces stable alloys in a controlled environment (glovebox) at room temperature but quickly decomposes to non-perovskite δ-CsPbI3, iodine, and metal oxides when exposed to air. The degradation mechanism of these materials was studied in detail using XPS techniques, revealing potential alternatives to produce stable Sn2+ containing perovskites with properties similar to those of cubic CsPbI3 at room temperature without solvents and increased stability under ambient conditions when Pb2+ was partially replaced with Sn2+.

Graphical abstract: Stability of CsPbI3 with divalent cations incorporated via mechanochemical alloying

Supplementary files

Article information

Article type
Paper
Submitted
11 Jan 2024
Accepted
25 Feb 2024
First published
18 Mar 2024
This article is Open Access
Creative Commons BY-NC license

Mater. Adv., 2024,5, 3742-3750

Stability of CsPbI3 with divalent cations incorporated via mechanochemical alloying

M. Shekarnoush, F. S. Aguirre-Tostado and M. Q. López, Mater. Adv., 2024, 5, 3742 DOI: 10.1039/D4MA00034J

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements