Plasmon bleaching dynamics in colloidal gold-iron oxide nanocrystal heterodimers.
Colloidal nanocrystal heterodimers composed of a plasmonic and a magnetic domain have been widely studied as potential materials for various applications in nanomedicine, biology, and photocatalysis. One of the most popular nanocrystal heterodimers is represented by a structure made of a Au domain and a iron oxide domain joined together. Understanding the nature of the interface between the two domains in such type of dimer and how this influences the energy relaxation processes is a key issue. Here, we present the first broad-band transient absorption study on gold/iron oxide nanocrystal heterodimers that explains how the energy relaxation is affected by the presence of such interface. We found faster electron-electron and electron-phonon relaxation times for the gold "nested" in the iron oxide domain in the heterodimers with respect to gold "only" nanocrystals, that is, free-standing gold nanocrystals in solution. We relate this effect to the decreased electron screening caused by spill-out of the gold electron distribution at gold/iron oxide interface.
NanoPhysics and NanoChemistry Units, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy. alberto.comin@iit.it
Alberto
A
Comin
Kseniya
K
Korobchevskaya
Chandramohan
C
George
Alberto
A
Diaspro
Liberato
L
Manna
D003102:Colloids / Q000737:chemistry; D019281:Dimerization; D005290:Ferric Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D013816:Thermodynamics
D003102:Colloids; D005290:Ferric Compounds; C000499:ferric oxide; D006046:Gold