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采用第一性原理计算方法,系统研究了不同宽度、不同边缘修饰模式的间隔氢吸附锯齿型石墨烯纳米带的压电性质.结构优化和结合能计算表明,氢修饰石墨烯纳米带结构稳定.氢原子间隔排列的吸附使得纳米带中的相邻碳原子成键及电荷状态不同,导致拉伸时纳米带中六元碳环的正负电荷中心不再重合,产生宏观电极化.纳米带宽度越宽,包含六元碳环数目越多,则拉伸时纳米带长度方向上电偶极矩密度越大,其压电性能越强.另外,边缘原子电荷状态决定了无拉伸时纳米带的初始电偶极矩密度,其大小可以通过改变边缘氢原子的修饰模式来有效调控.
The first-principles calculation method was used to systematically study the piezoelectric properties of hydrogen-bonding zigzag graphene nanoribbons with different widths and different edge modification modes. The structural optimization and binding energy calculations show that the structure of hydrogen-modified graphene nanoribbons is stable. Adsorption of the arrangement of hydrogen atoms makes the neighboring carbon atoms in the nanobelts bond and have different charge states, leading to the fact that the positive and negative charge centers of the six-membered carbon rings in the nanobelts are no longer coincident when stretched, resulting in macropolarization. The wider the number of carbocyclic rings containing six carbon atoms, the greater the piezoelectric dipole moment density in the direction of the length of the nanoribbons during stretching, and the stronger the piezoelectric property is. In addition, the state of the edge atomic charges determines the nanoribbons Of the initial electric dipole moment density, the size of which can be effectively modified by changing the edge of the hydrogen atom modification mode.