APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017;
New Orleans, Louisiana
Session V25: Focus Session Chemical Physics Frontiers at Interfaces III
2:30 PM–6:06 PM,
Thursday, March 16, 2017
Room: 288
Sponsoring
Unit:
DCP
Chair: Xiaoyang Zhu, Columbia University
Abstract ID: BAPS.2017.MAR.V25.6
Abstract: V25.00006 : Efficient Hot Electron Transfer by Plasmon Induced Interfacial Charge Transfer Transition
3:54 PM–4:30 PM
Preview Abstract
Abstract
Author:
Tianquan Lian
(Emory Univ)
Surface plasmon resonance in metal nanostructures has been widely used to
enhance the efficiency of semiconductors and/or molecular chromophore based
solar energy conversion devices by increasing the absorption or energy
transfer rate through the enhanced local field strength. In more recent
years, it has been shown that excitation of plasmons in metal nanostructures
can lead to the injection of hot electrons into semiconductors and enhanced
photochemistry. This novel mechanism suggests that plasmonic nanostructures
can potentially function as a new class of widely tunable and robust light
harvesting materials for solar energy conversion. However, plasmon-induced
hot electron injections from metal to semiconductor or molecules are still
inefficient because of the competing ultrafast hot electron relaxation
processes within the metallic domain.
In this paper we discuss a recent study on the plasmon-exciton interaction
mechanisms in colloidal quantum-confined semiconductor-gold nanorod
heterostructures. In CdSe NRs with Au tips, the distinct plasmon band of the
Au nanoparticles was completely damped due to strong interaction with the
CdSe domain. Using transient absorption spectroscopy, we show that optical
excitation of plasmons in the Au tip leads to efficient hot electron
injection into the semiconductor nanorod. In the presence of sacrificial
electron donors, this plasmon induced hot electron transfer process can be
utilized to drive photoreduction reactions under continuous illumination. We
propose that the strong metal/semiconductor coupling in CdSe/Au
hetersostructures leads to a new pathway for this surprising efficient hot
electron transfer. In this plasmon induced interfacial charge transfer
transition (PICTT) the a plasmon decay by direct excitation of an electron
from the metal to semiconductor, bypassing the competition with hot electron
transfer in metal. Ongoing studies are examining the generality of this
mechanism and exploring possible approaches for improving its efficiency
through controlling the size and shape of the plasmonic and excitonic
domains.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.MAR.V25.6