Studies on structural, optical, electrical and morphological properties of LiCoO ₂ thin films prepared by sol–gel method

In the present investigation, lithium cobalt oxide (LiCoO ₂ ) thin films were synthesised by the sol–gel process coupled with a cost-effective spin coating method using citric acid as a chelating agent. The films prepared on mineral glass substrates were annealed at different temperatures of 548–748 K in steps of 50 K. The XRD studies revealed that the LiCoO ₂ thin films annealed at a lower temperature exhibit semi-crystalline nature and transform to crystalline structure with an increase in the annealing temperature. The optical band gap energy of the films was found to vary from 2.51 to 3.24 eV for films annealed at temperatures in the range of 548–748 K. The electrical conductivity of the LiCoO ₂ thin films varied from 10 ⁻³ to 10 ⁻⁹  Ω ⁻¹  cm ⁻¹ due to variation in the annealing temperature.