The Effect of Wannier and Frenkel Exciton Resonance on the Luminescence Properties of Organic–Inorganic Layered Perovskite-Type Compounds

Abstract

We investigated the optical properties of organic–inorganic layered perovskite-type compounds that contained naphthylmethyl moieties in the organic layer. The Wannier exciton energy in the inorganic layer can be modulated by varying the halogen content. The Wannier or Frenkel exciton emissions in the organic layer were observed in compounds where the exciton energy was lower or higher than that of the triplet energy of the naphthylmethyl moiety, respectively. For the compounds with near-resonant Wannier and Frenkel exciton energies, luminescence was only observed at 490 and 500 nm from the naphthylmethyl moiety while luminescence at 520–566 nm was not detected. This selective quenching of the luminescence can be attributed to an enhancement in oscillator strength of near-resonant transition energies between Wannier and Frenkel excitons.