Predictions of moire excitons in twisted two-dimensional organic-inorganic halide perovskites.

ABSTRACT: Recent breakthrough in synthesizing arbitrary vertical heterostructures of Ruddlesden-Popper (RP) perovskites opens doors to myriad quantum optoelectronic applications. However, it is not clear whether moiré excitons and flat bands can be formed in such heterostructures. Here, we predict from first principles that twisted homobilayers of RP perovskite, MA₂PbI₄, can host moiré excitons and yield flat energy bands. The moiré excitons exhibit unique and hybridized characteristics with electrons confined in a single layer of a striped distribution while holes localized in both layers. Nearly flat valence bands can be formed in the bilayers with relatively large twist angles, thanks to the presence of hydrogen bonds that strengthen the interlayer coupling. External pressur

SUBMITTER: Zhang L 

PROVIDER: S-EPMC8098687 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature