Ultrafast Carrier Dynamics Affected by Shell Thickness in Inp/Zns Core/Shell Quantum Dots

Abstract

InP/ZnS core/shell QDs have demonstrated great applications in many fields due to their excellent luminescence performance. In this paper, the correlation between the ZnS shell thickness and the ultrafast carrier dynamics in InP/ZnS QDs was investigated by using the femtosecond time-resolved transient absorption spectroscopy and time-resolved photoluminescence techniques. We found that the thicker ZnS shell can confine more carriers to the InP core, thus effectively weaken the interactions between the carriers in core and the interfacial defect states, further resulting in the enhancement of the quantum yields and photoluminescence properties in InP/ZnS QDs.

Keywords: InP/ZnS core/shell quantum dots, Transient absorption spectrum, Nonlinear optics, Carrier dynamics, Shell thickness