Preparation of Li and Er codoped ZnO thin films and their photoluminescence

Abstract Li–Er codoped ZnO thin films have been prepared on Si(100) substrates by pulsed laser deposition (PLD). Both the as-grown and post-annealed films exhibit good crystalline quality with preferred c -axis orientation. After post-annealing at 850 °C, the photoluminescence (PL) related to intra-4 f shell of Er 3+ can be clearly observed. The Li–Er codoped ZnO film shows higher intensity of PL around 1.54 μm than the Er monodoped ZnO film. The behavior is attributed to the lowering of the symmetry of the crystal field around Er 3+ ions by introducing Li + into ZnO lattice, which is also confirmed by Raman scattering spectra.