標題: The Differences in Optical Characteristics of TiO2 and TiO2/AAO Nanotube Arrays Fabricated by Atomic Layer Deposition
作者: Chang, Yung-Huang
Liu, Chien-Min
Chen, Chih
Cheng, Hsyi-En
Lu, Tien-Chang
材料科學與工程學系
光電工程學系
Department of Materials Science and Engineering
Department of Photonics
公開日期: 2012
摘要: Self-aligned TiO2 nanotube arrays can be fabricated by atomic layer deposition (ALD) and anodic oxide template (AAO) on Si or quartz substrates. In this study, we compare the hetero-junction effects on optical characteristics of TiO2 nanotube arrays for the cases with AAO stayed intact and after AAO was etched away selectively. Due to the space confinement effect that can occur only in the TiO2/AAO nanotubes, the photoluminance intensity of TiO2 material is enhanced about 5 times for TiO2/AAO nanotubes compared with the TiO2 nanotubes. On the contrary, under 0 V bias, quantum efficiency of the TiO2/AAO nanotubes is 5.8 times lower than the TiO2 nanotubes because of higher probability for the recombination of photon-generated electron-hole pairs from the space confinement effect in TiO2/AAO nanotube arrays. When the bias reached 1 V, the TiO2 nanotubes still revealed more outstanding photon-to-electron transformation properties than the TiO2/AAO nanotubes. However, the quantum efficiency of TiO2/AAO nanotubes began to exceed TiO2 nanotubes when the bias is over 2 V. This phenomenon could result from the restraint of the recombination of photo-generated electron-hole pairs under high field strength and the increase in an amount of photo-generated carriers injected from AAO template. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.045205jes]
URI: http://hdl.handle.net/11536/16188
ISSN: 0013-4651
期刊: JOURNAL OF THE ELECTROCHEMICAL SOCIETY
Volume: 159
Issue: 5
結束頁: K136
顯示於類別:期刊論文


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