Photoluminescence properties of CuLa1−xLnxO2 (Ln: lanthanide)-intense and peculiar luminescence from Ln3+ at the site with inversion symmetry

► Ln3+ can be substituted for La3+ site in CuLa0.98Ln0.02O2 with inversion symmetry. ► Intense PL lines due to magnetic dipole transition were observed. ► Observed PL arose from transition probability increase of charge transfer absorption.