Synthesis and characterization of photochromic Ag-embedded TiO2 nanocomposite thin films by non-reactive RF-magnetron sputter deposition
Synthesis and characterization of photochromic Ag-embedded TiO2 nanocomposite thin films by non-reactive RF-magnetron sputter deposition
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DOI：
10.1016/j.apsusc.2012.04.054
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发表时间：
2012-07
影响因子：
6.7
通讯作者：
J. Zuo;P. Keil;G. Grundmeier
中科院分区：
文献类型：
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作者：
J. Zuo;P. Keil;G. Grundmeier
采用无反应射频磁控溅射法制备了具有可逆光致变色性能的银包埋tio2纳米复合薄膜。薄膜是在Ar/ o2和纯Ar气氛下生产的。在氧化状态下，观察到银从膜体向膜外表面扩散。因此，采用纯Ar等离子体沉积TiO2。tio2薄膜的电子和光学性质几乎不受氧存在的影响。利用透射电子显微镜（TEM）和反射模式x射线吸收光谱（XAS）研究了包埋银纳米粒子在退火前后的形貌、晶体结构和化学状态。薄膜的退火导致tio2基体的结晶。此外，薄膜中的银纳米粒子经历了奥斯特瓦尔德成熟，导致颗粒团聚。在溅射沉积和随后的退火过程中，没有发现包埋银的氧化，XAS测量证实了这一点。非反应性射频磁控管方法可以避免银包埋tio2纳米复合材料沉积过程中高能氧离子对银的攻击，从而使薄膜具有更好的光学性能和长期稳定性。
Ag-embedded TiO2nanocomposite thin film with reversible photochromic properties were prepared by layer-by-layer non-reactive RF-magnetron sputtering. Films were produced in Ar/O2and pure Ar atmospheres. In the oxidizing regime, a diffusion of Ag from the film volume to the outer film surface was observed. Therefore, pure Ar plasma was applied in the deposition of TiO2. The electronic and optical properties of the TiO2film were almost not affected by the presence of oxygen. Transmission electron microscopy (TEM) and reflection mode X-ray absorption spectroscopy (XAS) were performed to study the morphology, crystal structure and chemical state of the embedded Ag nanoparticles before and after the annealing step. Annealing of the film led to the crystallization of the TiO2matrix. Moreover, the Ag nanoparticles in the film underwent Ostwald ripening leading to particle agglomerate. No oxidation of the embedded Ag during the sputter deposition and subsequent annealing process was found as confirmed by XAS measurements. The non-reactive RF-magnetron method is believed to avoid the energetic oxygen ions attack to Ag during the deposition of Ag-embedded TiO2nanocomposite and thus the films are expected to have better optical properties and long-term stability.