用分子动力学和密度函数理论研究 -H和 -OH终结对Si-Si接触的粘附的影响
J David Schall1, Brian H Morrow2, Robert W Carpick3
1Mechanical Engineering Department, North Carolina A & T University, Greensboro, North Carolina 27411, United States.
Langmuir : the ACS journal of surfaces and colloids
|February 7, 2024
概括
随着表面覆盖率的减少,表面粘附率显著增加,形成共价键. 这解释了在滑动纳米度后粘附度增加的实验观测.
科学领域:
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
- 纳米技术纳米技术
背景情况:
- 了解粘附机制对于纳米级应用至关重要.
- 之前的研究表明,完全被动化表面的粘合力较低.
- 表面功能组 (-H和-OH) 在粘合中的作用需要进一步研究.
研究的目的:
- 模拟和分析纳米度和功能化基板之间的粘附.
- 为了研究表面覆盖和功能群 (-H, -OH) 对粘附的影响.
- 阐明控制表面粘附的原子层机制.
主要方法:
- 反应分子动力学 (MD) 模拟被用于模拟纳米度接触.
- 平面波密度函数理论 (DFT) 的计算被用来确定表面能量.
- 模拟考虑了具有不同-H和-OH功能组覆盖面的表面.
主要成果:
- 在完全覆盖 -H和 -OH时,粘附性较低,但由于共价键形成 (Si-Si和Si-O-Si),由于覆盖率降低,粘附性显著增加.
- 减少 -H 终端表面的覆盖率增加了粘附率约5倍,而 -OH 终端表面增加了约6倍.
- DFT和MD的计算证实了债券强度的顺序:Si-O>Si-H>Si-Si.
结论:
- 增强粘附性需要不和的表面部位,这表明了表面被动化去除的重要性.
- 这些发现支持了在滑动纳米度后粘附度增加的实验观测.
- 被动化物种的滑动诱导的去除是实验环境中增强粘附的可能原因.
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