Local Structural Properties and Growth Mechanism of ZnO Nanorods on Hetero-Interfaces.

We investigated the growth mechanism of ZnO(001) nanorods on SrTiO3(001) substrates. In the beginning of ZnO growth, a ZnO(110) film was developed on SrTiO3 substrates and then (001)-oriented ZnO nanorods grew on the ZnO(110) film. The strain energy of ZnO(110) growth on SrTiO3(001) planes was approximately 2.7 x 10(8) J/m3 whereas it was estimated to be ~1.61 x 10(9) J/m3 for ZnO(001) directly grown on SrTiO3(001) planes using Young's modulus of elasticity. Stress due to the lattice mismatch between ZnO and SrTiO3 was mostly relaxed in several monolayers and then ZnO(001) nanorods were finally formed along their easy growth directions. Keywords: ZnO Nanorod, Hetero-Interface, Local Structural, Growth Mechanism.