Structural, Electronic, and Mechanical Properties of 2D Oxidized Diamond (100) Nanofilms
Structural, Electronic, and Mechanical Properties of 2D Oxidized Diamond (100) Nanofilms
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DOI：
10.1002/adts.202100165
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发表时间：
2021-09
影响因子：
3.3
通讯作者：
Yaning Liu;Mengmeng Gong;Sun Jia;N. Gao;Hongdong Li
中科院分区：
文献类型：
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作者：
Yaning Liu;Mengmeng Gong;Sun Jia;N. Gao;Hongdong Li
在这项工作中，通过第一性原理计算研究了具有表面氧功能化的二维原子厚度金刚石（100）纳米膜的结构，电子和力学性质作为层数（n）的函数。声子色散曲线和从头算分子动力学结果证明了该结构在n ≥ 6时的动力学和热稳定性。氧化金刚石纳米膜的禁带宽度与膜层数无关，主要是由于表面原子对费米能级附近的导带和价带的贡献。用n从6到22的Perdew-Burke-Ernzerhof（PBE）计算表明，在最外侧两侧具有醚基团（一侧上的醚基团和另一侧上的氢官能团）的纳米膜的带隙在1.308-1.838 eV（1.803-1.884 eV）的范围内。在纳米薄膜的最外层两侧具有甲氧基丙酮基团（一侧为甲氧基丙酮基团，另一侧为氢官能团）的纳米薄膜的带隙值位于3.078-3.329 eV（3.135-3.302 eV）的区域，并且在费米能级附近的平坦的价带和导带使得直接带隙到间接带隙之间容易转变。计算的纳米薄膜的弹性常数和声速具有显著的宇称依赖振荡现象，并随着薄膜厚度的增加而增加。这项工作为制造2D金刚石基纳米器件（即，光电半导体器件、微纳机电系统）的高性能应用于实际领域。
In this work, the structural, electronic, and mechanical properties of 2D atomically thick diamond (100) nanofilms with surface oxygen functionalization as a function of layer number (n) are investigated by first‐principles calculation. The phonon dispersion curves and ab‐initio molecular dynamics results prove the dynamical and thermal stabilities of the structures at n ≥ 6. The bandgaps of oxidized diamond nanofilms are independent of the layer number, attributed to the main contribution of surface atoms to conductance bands and valence bands near the Fermi energy. The Perdew–Burke–Ernzerhof (PBE) calculations with n from 6 to 22 show that the bandgaps of nanofilms with ether groups on both outmost sides (ether groups on one side and hydrogen functional groups on the other side) are in the region of 1.308–1.838 eV (1.803–1.884 eV). The bandgap values of nanofilms with methoxyacetone groups on both outmost sides (methoxyacetone groups on one side and hydrogen functional groups on the other side) localized in the region of 3.078–3.329 eV (3.135–3.302 eV), and the flat valence bands and conduction bands near the Fermi energy make the easy transition between direct to indirect bandgaps. The calculated elastic constants and acoustic velocities of nanofilms have a significantly parity‐dependent oscillatory phenomenon and increase with increasing film thickness. This work provides new ideas for fabricating 2D diamond‐based nanodevices (i.e., optoelectrical semiconductor devices, micro‐ and nano‐electro‐mechanical systems) with high performances applied in practical fields.