Synthesis and characterization of electron beam evaporated LiCoO2 thin films

LiCoO2 thin films were prepared by electron beam evaporation technique using LiCoO2 target with Li/Co ratio 1.1 in an oxygen partial pressure of 5 x 10(-4) mbar. The films prepared at substrate temperature T-s<573 K were amorphous in nature, and the films prepared at T-s>573 K exhibited well defined (104), (101), and (003) peaks among which the (104) orientation predominates. The X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma (ICP) data revealed that the films prepared in the substrate temperature range 673-773 K are nearly stoichiometric. The grain size increases with an increase of substrate temperature. The Co-e(g) absorption bands, are empty and their peak position lies at around 1.7 eV above the top to the Co-t(2g) bands. The fundamental absorption edge was observed at 2.32 eV The films annealed at 1,023 K in a controlled oxygen environment exhibit (104) out plane texture with large grains.