Nanoepitaxy of Anatase-type TiO2 on CeO2 Nanocubes Self-Assembled on a Si Substrate for Fabricating Well-Aligned Nanoscale Heterogeneous Interfaces

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• 作者：Daisuke Hojo ; Takanari Togashi ; Takeo Ohsawa ; Mitsuhiro Saito ; Zhongchang Wang ; Yusuke Sakuda ; Shunsuke Asahina ; Yuichi Ikuhara ; Taro Hitosugi ; Tadafumi Adschiri
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：September 3, 2014
• 年：2014
• 卷：14
• 期：9
• 页码：4714-4720
• 全文大小：438K
• ISSN：1528-7505

文摘

Nanoscale epitaxy or nanoepitaxy for fabricating macroscopically well-aligned nanoscale heterogeneous interfaces on a Si substrate is demonstrated, combining bottom-up and top-down processes efficiently. TiO₂ sputtered in vacuum was selectively nucleated on the atomically flat surfaces of individual CeO₂ nanocubes prefabricated by self-assembly in solution on the substrate, and anatase-type TiO₂ was grown after a heat treatment by solid-phase epitaxy to produce tandem nanocrystals with heterogeneous interfaces. The atomic configurations of the tandem nanocrystals fabricated after sputtering and subsequent annealing were determined using high-resolution scanning transmission electron microscopy to characterize the nanoscale heterogeneous interfaces. Sharp heterogeneous interfaces were observed between the anatase TiO₂(001) and the CeO₂(001) nanocubes, with the TiO₂ [110] directions being parallel to the CeO₂ [100] directions. This unique nanoepitaxial growth technique will contribute to the development of devices and catalytic materials incorporating functional tandem nanocrystals with nanoscale heterogeneous interfaces.