Effect of Lattice Disorder on Exciton Dynamics in Copper-Doped InP/ZnSe x S 1- x Core/Shell Quantum Dots

• Published in: The journal of physical chemistry letters 2024-04, Vol.15 (16), p.4311-4318
• Main Authors: Chou, Kai-Chun, Li, Le-Chun, Tsai, Kai-An, Zeitz, David C, Pu, Ying-Chih, Zhang, Jin Z
• Format: Article
• Language: English
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.4c00689

InP/ZnSe S 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 S QDs in optoelectronics.