Donor and acceptor-like self-doping by mechanically induced dislocations in bulk TiO2
Donor and acceptor-like self-doping by mechanically induced dislocations in bulk TiO2
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DOI：
10.1016/j.nanoen.2021.105944
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发表时间：
2021-03-13
期刊：
影响因子：
17.6
通讯作者：
Froemling, Till
中科院分区：
文献类型：
--
作者：
Muhammad, Qaisar Khushi;Porz, Lukas;Froemling, Till
近年来，位错作为一种新的工具被引入到功能陶瓷的导电性定制中。然而，调谐策略受到对位错及其网络的结构复杂性的不良洞察的影响。在这里，我们证明，位错可以用来提高和降低在同一陶瓷材料的整体电导率。位错网络内的位错的排列的精确控制使得能够定制TiO 2块体样品，以表现得像是用受主或施主掺杂剂进行化学改性。我们的方法结合了超高压电子显微镜，氧分压，温度依赖性电导率测量结合飞行时间二次离子质谱。这使我们能够专注于下一个相邻位错的机械定制的相互作用，并区分导电路径和分离的电荷载流子区。这种看似简单的方法有目的地定制了TiO 2的导电性，为设计功能陶瓷开辟了新的途径，超越了常见的化学掺杂策略。
Dislocations have been recently introduced as a novel tool to tailor the conductivity of functional ceramics. However, tuning strategies suffer from poor insight into the structural complexity of dislocations and their networks. Here, we demonstrate that dislocations can be used to both enhance and reduce the overall conductivity in the same ceramic material. Accurate control of the arrangement of dislocations within the dislocation network enables tailoring TiO2 bulk samples to behave like being chemically modified either with an acceptor or donor dopant. Our approach combines ultra-high voltage electron microscopy, oxygen partial pressure, and temperature dependent electrical conductivity measurements combined with time-of-flight secondary ion mass spectrometry. This allows us to focus on mechanically tailored interaction of next neighbor dislocations and to differentiate between percolating conductive pathways and separated charge carrier zones. This seemingly simple approach purposefully tailors the conductivity of TiO2, opening new avenues to engineer functional ceramics beyond common chemical doping strategies.