In situ synchrotron radiation studies of functional materials prepared through CVD techniques

CVD 技术制备功能材料的原位同步辐射研究

基本信息

批准号：
EP/G067937/1
负责人：
Ivan Parkin
金额：
$ 19.02万
依托单位：
University College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FG067937%2F1
关键词：
situ synchrotron radiation studies functional

项目摘要

Chemical vapour deposition is an enormously important technique for the formation of thin films. It is the most widely used coating technique in industry for coatings especially for the flat glass industry where it is used to make energy efficient and self cleaning coatings through to the glass bottle industry where it is used to make low friction coatings ( total value > 10B pa). It is also one of the key techniques used in microelectronics for the fabrication of integrated circuits. Despite its immense value the study of the formation of CVD films by in situ analysis has been surprisingly sparse. Typically films are studied after deposition and cool-down and not as they are grown. Some in situ measurements have been made especially by elipsometry, Raman, and reflectometry techniques. Direct measurements of the growth process by XRD or by EXAFS has been difficult to achieve because the samples are in thin-film form typically contain few atomic layers (1-100 nm thick) and construction of reactors cells that accommodate the CVD experiment and the source have proved exacting. The process is only possible with a brilliant light source such as that provided by a synchrotron. The ability to study what is happening during the initial growth phases in a CVD process will bring immense benefit to understanding the process and will enable better design and control of a CVD experiment. For example to determine the position of a dopant atom in a structure and relate this to functionality and to understand how preferred orientation and growth changes during a CVD process. This has societal benefits- for example low-energy window coatings (such as K-glass) prepared by CVD have three times better performance if grown with the optimum growth direction. The performance of ZnO thin films for use as a transparent oxide conductor is magnified if grown with a (1 0 0) orientation. The position of the nitrogen dopant atom within titanium dioxide in N-doped titania is greatly effected by CVD conditions and both substitutional and interstitial doping is seen. However only the interstitial doping is important in extending the band gap and making a visible light photocatalyst. Such a material could find widespread usage as an antimicrobial coating for use in hospitals (to reduce MRSA transmission) and also as a visible light photocatalysts that can be used for water splitting. To realize that potential to improve on existing materials the growth process needs to be studied in detail and the conditions developed and understood that lead only to interstitial N- doping. Such complex problems can now be tackled with the next generation of synchrotron sources such as ESRF and DIAMOND.

化学蒸气沉积是形成薄膜的重要技术。它是涂料行业中使用最广泛的涂料技术，尤其是对于平坦的玻璃行业，它用于使能节能和自我清洁涂料通过玻璃瓶行业，用于制造低摩擦涂料（总价值> 10B PA）。它也是用于制造集成电路的微电子中使用的关键技术之一。尽管具有巨大的价值，但通过原位分析对CVD膜形成的研究仍然令人惊讶地稀疏。通常，在沉积和冷静后研究胶片，而不是随着生长而不是。某些原位测量尤其是通过电子测量法，拉曼和反射法技术进行的。很难通过XRD或EXAF对生长过程进行直接测量，因为样品以薄膜形式为薄膜通常包含很少的原子层（1-100 nm厚），并且可以适应CVD实验的反应器细胞的构建，并且证明源已被证明是严格的。只有使用同步加速器提供的明亮光源（例如亮光源）才能进行该过程。在CVD过程中研究最初生长阶段中发生的事情的能力将为理解该过程带来巨大的好处，并能够更好地设计和控制CVD实验。例如，确定掺杂原子在结构中的位置，并将其与功能联系起来，并了解CVD过程中的首选方向和生长如何变化。这具有社会利益 - 例如由CVD制备的低能量窗涂层（例如K玻璃），如果与最佳生长方向生长，则具有三倍的性能。如果以（1 0 0）方向生长，则将ZnO薄膜作为透明氧化物导体的性能放大。 CVD条件极大地影响了N掺杂的二氧化钛在二氧化钛在二氧化钛中的位置，并且可以看到替代性和间质掺杂。但是，只有间隙掺杂对于扩展带隙并制造可见光光催化剂很重要。这样的材料可以发现广泛的用法是用于医院的抗菌涂层（以减少MRSA传播），也可以作为可见的光光催化剂，可用于水分裂。为了意识到改善现有材料的潜力，需要详细研究增长过程，并了解并理解仅导致间质n倍率的条件。现在，可以使用下一代同步加速器来源（例如ESRF和Diamond）解决这样的复杂问题。