Mar 15, 2011
Integrating core/shell ferroelectric nanostructures on silicon substrates
Porous Si and Al2O3 have been used extensively as negative templates to form ferroelectric nanostructures by various methods. However, in order to expose the ferroelectric materials ready for application, it is necessary to etch away the templates. Damage to the nanostructures can occur during etching. To solve this problem, hydrothermal ZnO nanoarrays (ZNAs) have been employed as a positive template for ferroelectric BiFeO3 (BFO). Nevertheless, the fabrication of the ferroelectric shell in a basic hydrothermal environment resulted in dissolution of ZnO nanostructures. Therefore, sputtering was chosen to preparing the BFO shell. The result is a BFO/ZnO core/shell heterostructure.
Researchers at National Tsing Hua University, Taiwan, are busy studying the synthesis of BFO-covered ZNA core-shell heterostructures. The density, length and aligned behaviour of ZNAs have been found to strongly affect the formation of BFO/ZNA core/shell heterostructures.
According to the team, the synthesis approach integrates BFO/ZNA nanostructures to substrates, which can be utilized in optical and/or electronic applications. The ferroelectric, piezoelectric and photovoltaic properties of these BFO/ZNA heterostructures are being investigated.
More information can be found in the journal Nanotechnology.
About the author
S W Chen is a PhD candidate in Prof. J M Wu's group at the Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan. He is investigating the measurement and application of BFO-covered ZnO high aspect ratio nanostructures.