CHARGE TRANSFER. Efficient hot-electron transfer by a plasmon-induced interfacial charge-transfer transition

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Plasmon-induced hot-electron transfer in metal nanostructures offers a novel route for solar energy conversion.
• Low efficiencies in current devices are primarily due to hot-electron loss via ultrafast electron-electron scattering.

Purpose of the Study:

• To propose and demonstrate a new mechanism, plasmon-induced interfacial charge-transfer transition (PICTT), to enhance hot-electron transfer for solar energy applications.
• To overcome the limitations of conventional hot-electron transfer by minimizing energy loss.

Main Methods:

• Utilized gold (Au) nanodots on cadmium selenide (CdSe) nanorods as a model system.
• Investigated the damping of localized surface plasmons in gold through interfacial electron transfer to cadmium selenide.
• Analyzed the quantum efficiency and its dependence on excitation photon energy and polarization.

Main Results:

• Demonstrated efficient plasmon damping in Au-CdSe nanostructures via interfacial electron transfer.
• Achieved a high quantum efficiency for the PICTT process, exceeding 24%.
• Observed that the PICTT process's efficiency was independent of excitation photon energy over a 1 eV range and dependent on excitation polarization.

Conclusions:

• The plasmon-induced interfacial charge-transfer transition (PICTT) is a viable and efficient pathway for solar energy conversion.
• This mechanism effectively utilizes plasmon energy for direct electron excitation, bypassing loss mechanisms.
• The Au-CdSe system serves as a proof-of-concept for PICTT, highlighting its potential for future photovoltaic device development.