Resolving Enhanced Mn2+ Luminescence near the Surface of CsPbCl3 with Time-Resolved Cathodoluminescence Imaging

• Published in: The journal of physical chemistry letters 2020-04, Vol.11 (7), p.2624-2629
• Main Authors: Wai, Rebecca B, Ramesh, Namrata, Aiello, Clarice D, Raybin, Jonathan G, Zeltmann, Steven E, Bischak, Connor G, Barnard, Edward, Aloni, Shaul, Ogletree, D. Frank, Minor, Andrew M, Ginsberg, Naomi S
• Format: Article
• Language: English
• Subjects: imaging; Impurities; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; luminescence; perovskites; transition metals
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.0c00574

Mn2+ doping of lead halide perovskites has garnered recent interest because it produces stable orange luminescence in tandem with perovskite emission. Here, we observe enhanced Mn2+ luminescence at the edges of Mn2+-doped CsPbCl3 perovskite microplates and suggest an explanation for its origin using the high spatiotemporal resolution of time-resolved cathodoluminescence (TRCL) imaging. We reveal two luminescent decay components that we attribute to two different Mn2+ populations. While each component appears to be present both near the surface and in the bulk, the origin of the intensity variation stems from a higher proportion of the longer lifetime component near the perovskite surface. We suggest that this higher emission is caused by an increased probability of electron–hole recombination on Mn2+ near the perovskite surface due to an increased trap concentration there. This observation suggests that such surface features have yet untapped potential to enhance emissive properties via control of surface-to-volume ratio.