Enhanced Self-Assembly of Crystalline, Large-Area, and Periodicity-Tunable TiO2Nanotube Arrays on Various Substrates.
Due to their superior physical properties, titanium dioxide (TiO2) nanotube arrays are one of the most investigated nanostructure systems in materials science until now. However, it is still a great challenge to achieve damage-free techniques to realize controllable, cost-effective, and high-performance TiO2nanotube arrays on both rigid and flexible substrates for different technological applications. In this work, we demonstrate a unique strategy to achieve self-assemble crystalline, large-area, and regular TiO2nanotube arrays on various substrates via hybrid combination of conventional semiconductor processes. Besides the usual applications of TiO2as carrier transport layers in thin-film electronic devices, we demonstrate that the periodic TiO2nanotube arrays can show the effect of optical grating with large-area uniformity. Specifically, the fabricated nanotube geometries, such as the tube height, pitch, diameter, and wall thickness, as well as the crystallinity can be reliably controlled by varying the processing conditions. More importantly, utilizing these nanotube arrays in perovskite solar cells can further enhance the optical absorption, leading to improved power conversion efficiency. In contrast to other typical template-assisted fabrication approaches, we employ a soft template here, which would enable the construction of nanotube arrays without any significant damage associated with template removal. Furthermore, without the thermal restriction of underlying substrates, these crystalline nanotube arrays can be transferred to mechanically flexible substrates by a simple one-step method, which can expedite these nanotubes for potential utilization in other application domains.
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Xiaoguang
X
Liang
Heng
H
Zhang
Ho-Wa
HW
Li
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Lei
L
Shu
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
HoYuen
H
Cheung
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Dapan
D
Li
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
SenPo
S
Yip
Qing Dan
QD
Yang
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Chun-Yuen
http://orcid.org/0000-0003-4780-480X
CY
Wong
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Sai-Wing
SW
Tsang
Shenzhen Research Institute, City University of Hong Kong , 518057 Shenzhen, People's Republic of China.
Johnny C
http://orcid.org/0000-0003-3000-8794
JC
Ho
anatase; flexible substrate; nanotube; optical grating; perovskite solar cell; titanium dioxide