量子点量子阱结构中激子的极化效应(英文)

Polaron Effects on Excitons in a Quantum Dot Quantum Well Structure

考虑激子与体纵光学声子的相互作用,采用变分法研究了量子点量子阱结构中激子的极化效应.以CdS/HgS量子点量子阱结构为例进行数值计算,得到了激子的基态能量和束缚能.研究结果表明,声子对激子束缚能的贡献随着阱宽的增加而增加,极化子效应不能忽略.激子的基态能量和束缚能明显依赖于量子点量子阱结构的核半径和壳层厚度,量子点量子阱结构的尺寸对激子-声子相互作用有重要的影响.

The polaronic effect on the exciton in a spherical quantum dot quantum well (QDQW) structure is studied theoretically by using a variational approach.The interactions of an exciton with the longitudinal optical phonons are taken into account in the framework of the dielectric continuum approximation.The calculations are carried out for a CdS/HgS quantum dot quantum well structure.It is shown that the contribution of the phonons to the binding energy increases when the well width increases and the polaron effects are un-negligible.Both the ground state energy and the binding energy of exciton depends sensitively on the core radius and shell thickness of the QDQW structure.