1 research outputs found
Interface Engineering of Mn-Doped ZnSe-Based Core/Shell Nanowires for Tunable Host–Dopant Coupling
Transition
metal ion doped one-dimensional (1-D) nanocrystals (NCs)
have advantages of larger absorption cross sections and polarized
absorption and emissions in comparison to 0-D NCs. However, direct
synthesis of doped 1-D nanorods (NRs) or nanowires (NWs) has proven
challenging. In this study, we report the synthesis of 1-D Mn-doped
ZnSe NWs using a colloidal hot-injection method and shell passivation
for core/shell NWs with tunable optical properties. Experimental results
show optical properties of the NWs are controlled by the composition
and thickness of the shell lattice. It was found that both the host–Mn
energy transfer and Mn–Mn coupling are strongly dependent on
the type of alloy at the interface of doped core/shell NWs. For Mn-doped
type I ZnSe/ZnS core/shell NWs, the ZnS shell passivation can enhance
florescence quantum yield with little effect on the location of the
incorporated Mn dopant due to the identical cationic Zn<sup>2+</sup> site available for Mn dopants throughout the core/shell NWs. However,
for Mn-doped quasi type II ZnSe/CdS NWs and ZnSe/CdS/ZnS core/shell
NWs, the cation alloying (Zn<sub>1–<i>x</i></sub>Cd<sub><i>x</i></sub>SÂ(e)) can lead to metal dopant migration
from the core to the alloyed interface and tunable host–dopant
energy transfer efficiencies and Mn–Mn coupling. As a result,
a tunable dual-band emission can be achieved for the doped NWs with
the cation-alloyed interface. The interfacial alloying mediated energy
transfer and Mn–Mn coupling provides a method to control the
optical properties of the doped 1-D core/shell NWs