Origin of significant visible-light absorption properties of Mn-doped TiO"2 thin films
Origin of significant visible-light absorption properties of Mn-doped TiO"2 thin films
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DOI：
10.1016/j.actamat.2012.01.006
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发表时间：
2012-03
期刊：
影响因子：
9.4
通讯作者：
X. Xia;L. Lu;A. Walton;M. Ward;X. Han;R. Brydson;Jikui Luo;G. Shao
中科院分区：
文献类型：
--
作者：
X. Xia;L. Lu;A. Walton;M. Ward;X. Han;R. Brydson;Jikui Luo;G. Shao
这是非常可取的诱导显着红移的光吸收边的TiO2相，使这类低成本和环境友好的材料，可以用作有效的光吸收材料在新型光伏电池的长期可持续性或智能光催化剂超出紫外线范围。本工作的重点是研究锰诱导的红移的机制相结合的理论模型与先进的结构和光谱表征的掺杂薄膜，旨在提供有效的掺杂，通过提高掺杂原子和缺陷之间的相互作用所产生的掺杂化学的理解的基础指导。结果表明，Mn原子掺杂到Ti晶格位置与氧化价高于+3，导致在修改能带结构，以实现显着的光学红移的最大化的效果。氧空位的存在降低了Mn的价态及其红移效应，但由于它们与Mn原子的结合，它们在产生局部缺陷能级方面的不利影响降低了，使得Mn掺杂在激活TiO 2的各种可见光功能方面非常有前途。
It is highly desirable to induce significant red-shift in the optical absorption edges of TiO2phases so that this class of low-cost and environmentally friendly materials can be used as effective optical absorbing materials in novel photovoltaic cells with long-term sustainability or smart photo-catalysts beyond the ultraviolet range. This work focuses on studying the mechanisms of Mn-induced red-shift by combining theoretical modeling with advanced structural and spectroscopic characterization of doped thin films, aiming to provide fundamental guidance for effective doping through enhanced understanding of doping chemistry resulting from the interplay between doping atoms and defects. It is shown that Mn atoms doped into the Ti lattice sites are associated with oxidation valency higher than +3, resulting in maximized effectiveness in modifying the band structure to achieve remarkable optical red-shifting. The presence of oxygen vacancies reduces the Mn valency and its red-shifting effect, but their detrimental effect in bringing about localized defect levels is reduced owing to their association with Mn atoms, making Mn doping highly promising in activating various visible light functionalities of TiO2.