Influence of lithium on structure and optical properties of lanthanum doped yttrium oxide thin films

Luminescence emission of lithium incorporated lanthanum doped yttrium oxide thin films are studied. The films were prepared by spray pyrolysis method at 375 ± 10 °C. The crystallites sizes were evaluated and found to be ~50 nm from the X-ray diffraction peak. The feature of surface morphology was obtained by field emission scanning electron microscope. Fourier transformed infrared spectrum represent absorption peak is at 875 cm−1. Optical absorption peak at 260 nm reveals the red shift in Li doped samples with energy gap 5.42 eV. Photoluminescence emissions are at 317, 390, 428 and 612 nm. Gamma-irradiated films shows TL glow peaks at 465 K and 588 K and their corresponding activation energies and the frequency factors were found to be 0.56 eV, 1.1 MHz and 0.6 eV, 0.3 MHz respectively. The incorporated Li ions played a vital role to decrease the processing temperature with the improved the morphological features.