Molecular-mediated crystal growth of PbTiO3 nanostructure on silicon substrate

A simple approach based on an organically modified sol-gel process has been developed to fabricate PbTiO3 (PT) nanocrystals on Si (1 0 0) substrate, where the amorphous powder modified by acetylacetone (acac) was used as precursor. After dropping the amorphous powder precursor prepared by freeze-drying process, PT nanocrystals on Si (1 0 0) substrate were obtained after heat treatment at 720 °C for 30 min in air. PT nanocrystals have been detected by XRD to be tetragonal perovskite structure. With the increase of acac/Pb molar ratio, the relative (1 0 0)/(0 0 1) diffraction peak intensity gradually increases, which probably suggested an oriented growth of PT nanocrystal along [1 0 0] on Si (1 0 0) substrates. In addition, Atomic force microscopy (AFM) results indicated that the height and the average lateral size of PT nanocrystal increased and then decreased as the acac/Pb molar ratio increased. Piezoelectric force microscopy (PFM) results demonstrated that all the samples show obvious piezoelectric activity. These results implied that the acetylacetone molecular mediated the growth of PT nanocrystals on Si (1 0 0) substrates possibly by the acac/Pb molar ratio. This simple method has been suggested to be attractive for tailoring an oriented growth of the nanostructures of perovskite oxide systems on Si substrates.

► The amorphous powder modified by acetylacetone (acac) was used as precursor. ► The precursor was prepared by the sol-gel with the subsequent freeze-drying process. ► The PbTiO3 nanostructure on Si (1 0 0) substrate with tetragonal shapes and uniform sizes were successfully achieved. ► It was found that the molar ratio of acac/Pb plays an important role in the PT nanostructure growth on the Si (1 0 0) substrates.