Native defects affecting the Li atom distribution tune the optical emission of ZnO: Li epitaxial thin film

摘要

It is found that the oxygen vacancy (V_o) defect concentration affecting the separation between individual species in Li_(Zn)-Li_i complex influences the optical emission property of Li_(0.06)Zn_(0.94)O epitaxial thin film grown by pulsed laser deposition. The film grown under low oxygen partial pressure (n-type conductivity)/higher partial pressure (resistive-type) has broad emission at ～2.99 eV/～2.1 eV and a narrower emission at 3.63 eV/3.56 eV, respectively. First principle based mBJLDA electronic structure calculation suggests that the emission at 2.99 eV is due to the Li_(Zn)-Li_i pair complex and the emission at 2.1 eV is when the component species are away from each other.