Lithium ions were implanted at low energies (40 and 50 keV) and at a dosage of 5 × 1013 ions/cm2 over 〈0 0 2〉 ZnO thin films that had been deposited by pulsed laser deposition. The implanted samples were subsequently treated by rapid thermal annealing at 750 °C. Scanning electron microscopy images revealed improved grain formation for the implanted samples. However, a presence of microvoids was also observed in these samples; the amount of microvoids tended to increase on high-temperature annealing. Dominant donor-bound-exciton peaks is observed in all the samples along with some defect related to the exciton bound peaks although with a lesser intensity compared to as-deposited sample. © 2012 Elsevier Ltd. All rights reserved.