Si(111)表面上Ge量子点的理论研究

Theoretical Study on Ge Quantum Dots on the Si(111)Surface

采用DFTB+计算方法对在Si(111)表面上三种不同形状的Ge量子点结构(六边形岛状量子点、条形岛状量子点以及光栅形量子点)进行结构优化,并采用CASTEP对结构的能量及光学性质进行计算。对这几类Ge量子点表面纳米结构的光学性质(介电函数、光吸收、复折射率、反射率)进行深入分析,经过比较后会发现这三种结构中光吸收能力最好的结构是条形岛状量子点纳米结构。

The nanostructures wi th three kinds of Ge quantum dots （ including the island quantum dot , strip quantum dot,and grating quantum dot） in the surface of Si（111） were optimized by the calculation method of DFTB＋ , the energy and optical properties of nanostructures were calculated by CASTEP. The corresponding optical properties of dielectric function, optical absorption, refractive index and reflectivity were discussed, and fond that the optical absorption of strip quantum dot is the largest among the three Ge quantum dots.