文章基本信息

标题：Control of crystallographic orientation in diamond synthesis through laser resonant vibrational excitation of precursor molecules
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作者：Zhi Qiang Xie ; Jaeil Bai ; Yun Shen Zhou 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2014
卷号：4
DOI：10.1038/srep04581
出版社：Springer Nature
摘要：Crystallographic orientations determine the optical, electrical, mechanical, and thermal properties of crystals. Control of crystallographic orientations has been studied by changing the growth parameters, including temperature, pressure, proportion of precursors, and surface conditions. However, molecular dynamic mechanisms underlying these controls remain largely unknown. Here we achieved control of crystallographic orientations in diamond growth through a joint experimental and theoretical study of laser resonant vibrational excitation of precursor molecules (ethylene). Resonant vibrational excitation of the ethylene molecules using a wavelength-tunable CO₂ laser steers the chemical reactions and promotes proportion of intermediate oxide species, which results in preferential growth of {100}-oriented diamond films and diamond single crystals in open air. Quantum molecular dynamic simulations and calculations of chemisorption energies of radicals detected from our mass-spectroscopy experiment provide an in-depth understanding of molecular reaction mechanisms in the steering of chemical reactions and control of crystallographic orientations. This finding opens up a new avenue for controlled chemical vapor deposition of crystals through resonant vibrational excitations to steer surface chemistry.