Coexistence of carbonyl and ether groups on oxygen-terminated (110)-oriented diamond surfaces
Coexistence of carbonyl and ether groups on oxygen-terminated (110)-oriented diamond surfaces
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DOI：
10.1038/s43246-022-00228-4
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发表时间：
2022-01-28
影响因子：
7.8
通讯作者：
Maurer, Reinhard J.
中科院分区：
文献类型：
--
作者：
Chaudhuri, Shayantan;Hall, Samuel J.;Maurer, Reinhard J.
金刚石的化学气相沉积通常会导致（110）晶面的更快生长，但实现大面积和高质量的表面具有挑战性，并且需要生长后处理。在这里，作者提出了一个系统的表征氧终止金刚石（110）表面的结构和稳定性。金刚石基材料具有独特的性能，在许多电化学，光学，热学和量子应用开发。当通过化学气相沉积（CVD）生长时，（110）面的生长速率通常比其他两个主要结晶取向（111）和（100）快得多。因此，获得足够大面积和高质量的（110）取向晶体是具有挑战性的，并且通常需要表面的生长后处理。虽然CVD生长在金刚石表面上赋予氢终止，但大多数生长后处理程序使表面氧终止，这反过来影响材料的表面性质。在这里，我们使用密度泛函理论计算和X射线光电子能谱实验的组合来确定（110）表面的氧化状态。我们表明，在0-1000 K的温度范围内，（110）表面的相图是由共存和相邻的羰基和醚基团的高度稳定的相为主，而过氧化物基团的稳定性增加，在低温和高压。我们提出了一种混合羰基醚相的形成机制，并合理化其高稳定性。我们进一步证实了我们的研究结果，通过比较模拟的核心水平的结合能与实验的X射线光电子能谱数据的最高质量的（110）取向的金刚石晶体表面的报告。
Chemical vapor deposition of diamond typically results in the faster growth of the (110) facet, but achieving large-area and high-quality surfaces is challenging and requires post-growth processing. Here, the authors present a systematic characterization of the structure and stability of oxygen-terminated diamond (110) surfaces.Diamond-based materials have unique properties that are exploited in many electrochemical, optical, thermal, and quantum applications. When grown via chemical vapor deposition (CVD), the growth rate of the (110) face is typically much faster than the other two dominant crystallographic orientations, (111) and (100). As such, achieving sufficiently large-area and high-quality (110)-oriented crystals is challenging and typically requires post-growth processing of the surface. Whilst CVD growth confers hydrogen terminations on the diamond surface, the majority of post-growth processing procedures render the surface oxygen-terminated, which in turn impacts the surface properties of the material. Here, we determine the oxygenation state of the (110) surface using a combination of density functional theory calculations and X-ray photoelectron spectroscopy experiments. We show that in the 0-1000 K temperature range, the phase diagram of the (110) surface is dominated by a highly stable phase of coexisting and adjacent carbonyl and ether groups, while the stability of peroxide groups increases at low temperatures and high pressures. We propose a mechanism for the formation of the hybrid carbonyl-ether phase and rationalize its high stability. We further corroborate our findings by comparing simulated core-level binding energies with experimental X-ray photoelectron spectroscopy data on the highest-quality (110)-oriented diamond crystal surface reported to date.