Yijun Zhang, Ming Liu, Bin Peng, Ziyao Zhou, Chenying Wang, Weixuan Jing, Zhuang-De Jiang, Wei Ren, and Zuo-Guang Ye,Temperature induced interface and optical properties of the multi-layer nanotube network,Journal of Applied Physics 123, 224102. (2018)Full text
The ever-increasing demand for larger surface area, well-defined, and conformal multi-layer nanostructures in gas sensor, catalyst and solar cell applications has propelled the exploration of such nanostructures within an atomic resolution. The atomic layer deposition (ALD) technique is ideal for the synthesis of these nanostructures due to its excellent step coverage ability on high aspect ratio nanostructures. In this work, different coaxial nanotube networks are successfully fabricated by electrospinning and ALD, with a well-controlled phase. We systematically studied the temperature-induced microstructures and photoluminescence property evolution of the nanotube network. The Al2O3/ZnO/Al2O3 tri-layer nanotube network is obtained by sintering at 400 °C, and a ZnAl2O4 core-shell nanotube structure has formed by the Kirkendall effect by further post-annealing at 700 °C. Oxygen accumulation is clearly observed at the small neck feature, but the Zn and Al elements are uniformly distributed along the whole nanotube. Photoluminescence emission obtained in this work is so broad that it almost covers the whole visible light wavelength range. The results indicate that the microstructures and photoluminescence properties can be well-controlled by the post-annealing temperature. It provides an available platform for realizing conformal 3D nano-devices.