论文部分内容阅读
在水相合成CdTe以及CdTe/CdS核壳结构量子点基础上,利用基于抽运-探测技术的瞬态差分透射技术研究了CdTe量子点以及不同CdS壳层厚度的CdTe/CdS量子点的最低激子能态的超快激发与弛豫动力学.研究表明:相比于CdTe,CdTe/CdS量子点的电子空穴由于空间分离,其所需的激发时间要长于电子空穴空间重叠态所需要的激发时间.随着壳层厚度的增加,量子点表面的钝化有效地减少了表面态相关弛豫机理,并延长相对应的弛豫时间.
Based on the quantum dots synthesized by aqueous phase and CdTe / CdS core-shell quantum dots, the lowest differential excitation of CdTe quantum dots and CdTe quantum dots with different CdS shell thickness was studied by using transient differential transmission technique based on the pump-probe technique Ultra-fast excitation and relaxation dynamics of sub-energy states.The results show that compared with CdTe, the electron-hole in CdTe / CdS QDs is separated by space and the required excitation time is longer than that needed for electron-hole space overlap Of the excitation time.With the increase of shell thickness, the passivation of the quantum dot surface effectively reduces the surface-state relaxation mechanism and prolongs the corresponding relaxation time.