posted on 2020-03-19, 16:35authored byRebecca
B. Wai, Namrata Ramesh, Clarice D. Aiello, Jonathan G. Raybin, Steven E. Zeltmann, Connor G. Bischak, Edward Barnard, Shaul Aloni, D. Frank Ogletree, Andrew M. Minor, Naomi S. Ginsberg
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.