Crystal orientation dependent thermoelectric properties of highly oriented aluminum-doped zinc oxide thin films

We demonstrate that the thermoelectric properties of highly oriented Al-doped zinc oxide (AZO) thin films can be improved by controlling their crystal orientation. The crystal orientation of the AZO films was changed by changing the temperature of the laser deposition process on LaAlO3 (100) substrates. The change in surface termination of the LaAlO3 substrate with temperature induces a change in AZO film orientation. The anisotropic nature of electrical conductivity and Seebeck coefficient of the AZO films showed a favored thermoelectric performance in c-axis oriented films. These films gave the highest power factor of 0.26Wm(-1) K-1 at 740 K. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790644]