Effect of Lattice Disorder on Exciton Dynamics in Copper-Doped InP/ZnSe<sub><i>x</i></sub>S<sub>1–<i>x</i></sub> Core/Shell Quantum Dots
Kai-Chun Chou, L. Y. Li, Kai‐An Tsai, David C. Zeitz, Ying‐Chih Pu, Jin Z. Zhang
Abstract
InP/ZnSe x S 1– x core/shell quantum dots (QDs) with varying Cu concentrations were synthesized by a one-pot hot-injection method. X-ray diffraction and high-resolution transmission electron microscopy results indicate that Cu doping did not alter the crystal structure or particle size of the QDs. The optical shifts in UV–visible absorption and photoluminescence (PL) suggest changes in the electronic structure and induction of lattice disorder due to Cu doping. Ultrafast transient absorption spectroscopy (TAS) reveled that a higher Cu-doping level leads to faster charge carrier recombination, likely due to increased nonradiative decay from defect states. Time-resolved PL (TRPL) studies show longer average lifetimes of charge carriers with increased Cu doping. These findings informed the development of a kinetic model to better understand how Cu-induced disorder affects charge carrier dynamics in the QDs, which is important for emerging applications of Cu-doped InP/ZnSe x S 1– x QDs in optoelectronics.