Effect of lithium salt precursors on the physical properties of ZnO-Li thin films

Zinc oxide (ZnO) thin films were prepared on glass substrates with three different lithium salt precursors (acetate, chloride and nitrates) with Li/Zn atomic ratio varying between 0% and 20% using sol-gel deposition and spin-coating technique. The aim of the work was to compare the physical properties of lithium containing ZnO thin layers obtained using different Li salt precursors; in order to identify the most suitable one. The X-ray diffraction measurements showed that all 500 degrees C annealed films were polycrystalline. The samples prepared from lithium nitrates solutions showed a preferred orientation along c-axis (002) and their crystallites sizes are much larger compared to other Li source. The ultraviolet-visible transmission spectra confirmed the good transparency of all ZnO films with an average transmission around 85 % in the visible range. The optical band gap values varied between 3.19 eV and 3.28 eV. All the results revealed that the ZnO-Li films prepared with LiNO3 exhibit the highest crystallographic quality and the best optical and electrical properties compared to C2H3LiO2 and LiCl containing precursors.

Automated summary

In this study, zinc oxide thin films containing lithium were prepared using different lithium salt precursors, with films prepared using lithium nitrates showing the highest crystallographic quality and best optical and electrical properties. All ZnO films exhibited good transparency with an average transmission around 85% in the visible range.