Orientation Control of Two-Dimensional Perovskites by Incorporating Carboxylic Acid Moieties

[Image: see text] Two-dimensional perovskite compounds, (RNH(3))(2)PbX(4), have attracted much attention as quantum confinement materials. To achieve suitable orientation and exciton properties for optical applications, carboxy groups were introduced into the ammonium cations of two-dimensional perovskite compounds, which formed dimer structures based on the hydrogen bonding by the carboxy moieties. This structural organization allowed control of the layer orientation for favorable solar cells and thermal stability of the perovskites, while maintaining quantum confinement effects.