Polarized perovskite luminescence

Abstract

Nanomaterials Optical elements can generate circularly polarized luminescence (CPL), but sources that directly emit CPL are desirable for many applications. Kim et al. synthesized formamidinium lead bromide nanocrystals (NCs) with mixtures of longer achiral ligands and shorter chiral ( R )-2-octylamine. Lower fractions of the chiral ligand formed smaller NCs that had stronger CPL at room temperature, apparently because these NCs have a higher fraction of chiral ligands that also have stronger electronic interactions with their perovskite cores. The perovskite NCs exhibited a luminescence dissymmetry g-factor of ∼0.06 at wavelengths between 520 and 540 nanometers. Although purification steps removed some of the chiral ligand, CPL could be restored in thin films with the addition of ( R )- or ( S )-methylbenzylammonium bromide. ACS Nano 14 , 8816 (2020).