Influence of Thermal Treatment of a Calcium Cobalt Oxide Thin Film by Rapid Thermal Annealing

Ca3Co4O9 thin films were deposited by using a sol-gel method. The films were treated by rapid thermal annealing, which is a fast and simple process. We measured and analyzed the electrical, structural, and optical properties. The Ca3Co4O9 structure changed at temperature above 750 °C, which changed the electrical and the thermal properties. In addition, the thin films similar electrical and structural results when treated in a furnace at 850 °C, which results were confirmed by Xray diffraction, Raman spectroscopy, and a Hall measurement system. Therefore, rapid thermal annealing can produce Ca3Co4O9 thin films for thermoelectric materials.