Tailoring orientation of microstructure for improving thermopower factor in Mg-doped CuCrO₂ thick films

This study changed the material thickness (0.5-2.7 mu m) to control the orientation of microstructure for tailoring the thermopower factor of CuCr0.85Mg0.15O2 films. As a result, the (110)-preferred orientation and copper vacancies were dominant in the thicker film, which increased conductivity sigma. The Seebeck coefficient S remained unchanged within the wide film thickness range despite the remarkable increment in sigma. Therefore, the thermopower factor (PF = S-2 sigma) of the CuCr0.85Mg0.15O2 films drastically increased with the increase in the film's thickness, reaching 720 mu W/mK(2) at 500 & DEG;C in a 2.0 mu m-thick CuCr0.85Mg0.15O2 film. This value is better than that observed in the bulk materials. A detailed discussion of physical mechanisms is presented in this manuscript.