Surface plasmons and hot electrons

In summary, surface plasmons are responsible for the charge carriers that the water splitting device uses to split water. The plasmons arise from the interaction of the surface of the device with the surrounding water. The plasmons decay into electron-hole pairs, which are responsible for the reduction of water.
  • #1
prehisto
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Hello,Im reading a article about water spliting device in which all necessary charge carriers for water spliting arise from surface plasmons.

This is the article:
http://www.nature.com/nnano/journal/v8/n4/full/nnano.2013.18.html#f1

So i do not understand how charge carriers arise form surface plasmons.
Could someone help me with this?
Meiby give me some kind a link where surface plasmons and hot electrons are explained.So far I haven't found any article which gives qualitative explanation of surface plasmons and charge carries.
 
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  • #2
They write that the plasmons decay into electron-hole pairs.
This happens also for bulk plasmons, when their wavenumber is large enough.
See e.g. Fig. 5.5 in the following document:
http://www.lptl.jussieu.fr/files/chap_eg(1).pdf
 
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  • #3
Thanks for the reference to decay.
Im sorry,but i can't make sense of fig.5.5
 
  • #4
The gray shaded area is the region where particle hole excitations are possible.
Where the line ##\omega_p## lies inside this region, the plasmon can decay rapidly into particle hole pairs. Thats also what happens in the gold nanorods you are interested in.
Basically, the nanorod acts as a gigant antenna whose resonance frequency is determined by the surface plasmon resonance, but the oscillation of the charges is strongly damped as they decay into electron hole pairs. These separate and wander into the platinum grains or cobaltum oxide where they reduce/ oxidize water.
 
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  • #5
DrDu said:
The gray shaded area is the region where particle hole excitations are possible.
Where the line ##\omega_p## lies inside this region, the plasmon can decay rapidly into particle hole pairs. Thats also what happens in the gold nanorods you are interested in.
Basically, the nanorod acts as a gigant antenna whose resonance frequency is determined by the surface plasmon resonance, but the oscillation of the charges is strongly damped as they decay into electron hole pairs. These separate and wander into the platinum grains or cobaltum oxide where they reduce/ oxidize water.

I m sorry but I have further questions about the graphic.
What is ω_(-) and what is ω_(+)? Are they just notation for graphical boundaries?
And K_F stands for wave number?
 
  • #6
k_F is the Fermi wavenumber, i.e the maximal wavenumber electrons in have in a Fermi gas at zero temperature.
The two omegas are simply the limits above/below which electron-hole pairs exist.
 
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FAQ: Surface plasmons and hot electrons

Question 1:

What are surface plasmons?

Surface plasmons are collective oscillations of electrons at the surface of a metal when excited by light. They are responsible for the enhanced electromagnetic fields and energy transfer that occur at the interface between a metal and a dielectric material.

Question 2:

How are surface plasmons generated?

Surface plasmons are generated when photons from incident light interact with conduction electrons in the metal surface, causing them to oscillate at the same frequency as the incident light. This can occur through several mechanisms, including prism coupling, grating coupling, or nanoparticle interactions.

Question 3:

What are hot electrons?

Hot electrons are high-energy electrons that are generated when surface plasmons decay. They have a higher kinetic energy than the Fermi energy of the metal and can be harnessed for various applications, such as photocatalysis, sensing, and photovoltaics.

Question 4:

What is the role of hot electrons in surface plasmonics?

Hot electrons play a crucial role in surface plasmonics as they are responsible for the enhanced optical properties of plasmonic materials. They can transfer their energy to nearby molecules, leading to chemical reactions or fluorescence, and can also be used to generate photocurrent in photovoltaic devices.

Question 5:

What are some potential applications of surface plasmons and hot electrons?

Surface plasmons and hot electrons have a wide range of potential applications, including sensing, imaging, energy harvesting, and phototherapy. They can also be used in nanophotonics for subwavelength optical manipulation and in plasmonic devices for information processing and communication.

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