Enhanced transparent conducting performance of c-axis oriented Ca3Co4O9 thin films†
p-type transparent conductive Ca3Co4O9 thin films were grown on LaAlO3 substrates using a pulsed laser deposition technique. The films showed perfect c-axis orientation with a resistivity of about 7.3 mΩ cm at room temperature and optical transmittance of about 50% in the visible range. A high figure of merit of about 988 MΩ−1 was achieved in these c-axis oriented Ca3Co4O9 films, which is comparable to those reported for the state-of-the-art p-type transparent conducting oxides. This work demonstrated the potential applications of c-axis oriented Ca3Co4O9 films in optoelectronic devices as a new class of transparent conducting oxide coatings.