硅量子点中的孪晶对其电子结构和光学性能的影响

The Electronic Structure and Optical Properties of Silicon Quantum Dots are Affected by the Twin Crystal in Silicon Quantum Dots

以具有代表性的单孪晶和五重孪晶作为研究对象,运用密度泛函理论研究了孪晶结构的硅量子点的形成、稳定性、量子限域效应以及光学性质.结果表明,孪晶结构的硅量子点从热力学角度看是可以形成的,且孪晶结构可以增强硅量子点的稳定性;孪晶的存在使得硅量子点的量子限域效应和光学吸收减弱.

In this paper,the formation,stability,quantum confinement effect and optical properties of the silicon quantum dots（ Si QDs） with twin structure are studied by using the density functional theory. The research object is represented by single-twined and fivefold-twined silicon quantum dots. It is found that the formation of twinned Si QDs is thermodynamically possible and twinning enhances the stability of Si QDs. Both the quantum confinement effect and light absorption are weakened by twinning for Si QDs.