Exciton physics in organic-inorganic 2D perovskites

Organic-inorganic (hybrid) 2D perovskites (2DPKs) is an emerging class of layered materials that feature unique structural characteristics related to the soft and dynamic nature of their lattice structure and organic-inorganic interfaces. There is still little knowledge of the interplay between the physical and structural characteristics. Here, using optical spectroscopy and magneto-absorption, coupled with structural probes, we report the dependence of the formation, dynamics, and recombination of exciton states on the structural and compositional details of 2DPKs . Our work reveals the changes in the exciton properties due to the tuning of the 2DPKs thickness and the size of the organic molecules in the lattice [1]. Moreover, we demonstrate the existence of unique electronic states located at the edge surfaces of 2DPKs that are beneficial for optoelectronic applications [2,3]. Finally, we provide insight into the hetero-coupling between 2D perovskites and monolayer WS₂, which yield photoluminescence enhancement by more than one order of magnitude as compared to their constituent [4].

[1] J.-C. Blancon et al., Nat. Commun. 9, 2254 (2018).
[2] J.-C. Blancon et al., Science 355, 1288 (2017).
[3] H. Tsai et al., Nature 536, 312 (2016).
[4] A. Yang et al., Nano Lett. 19, 4852 (2019).