Effect of different surface coverages of transition metals on the electronic and structural properties of diamond
Effect of different surface coverages of transition metals on the electronic and structural properties of diamond
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DOI：
10.1002/pssa.201200027
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
Amit K. Tiwari;J. Goss;P. Briddon;Nicholas G. Wright;A. Horsfall;M. Rayson
中科院分区：
文献类型：
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作者：
Amit K. Tiwari;J. Goss;P. Briddon;Nicholas G. Wright;A. Horsfall;M. Rayson
金刚石表面上吸附物的存在，即使在相对较小的浓度，强烈影响电，化学和结构特性。尽管在技术上具有重要意义，但过渡金属对金刚石的覆盖相对较少受到关注。在本文中，我们给出了密度泛函计算的结果，研究了（001）金刚石表面上过渡金属的单层。我们发现，添加碳化物形成物质，如Ti，导致在所有表面覆盖率相对于非碳化物形成物质显著更高的吸附能。对于Cu的单层覆盖和Ti的亚单层覆盖，我们发现负电子亲和力。我们认为，基于电子亲和能和结合能，金属封端的（001）金刚石表面是电子发射器件应用的有希望的候选者。
The presence of adsorbate species on diamond surfaces, even in relatively small concentrations, strongly influences electrical, chemical and structural properties. Despite the technological significance, coverage of diamond by transition metals has received relatively little attention. In this paper, we present the results of density functional calculations examining up to a mono‐layer of transition metals on the (001) diamond surface. We find that addition of carbide forming species, such as Ti, results in significantly higher adsorption energies at all surface coverages relative to non‐carbide forming species. For monolayer coverage by Cu, and sub‐monolayer coverage by Ti, we find a negative electron affinity. We propose that based upon the electron affinities and binding energies, metal‐terminated (001) diamond surfaces are promising candidates for electron emission device applications.