What is the work function of graphene sheets?

In summary, the conversation discusses different values found for graphene depending on the growth method and environment, and the possibility of using graphene on copper for an ionizer to generate electrons. The topic of carbon oxides and surface-related effects such as photoelectric and thermal radiation is also mentioned. The potential for a low-cost photoelectric cell using graphene is briefly discussed as well.
  • #1
Javier Lopez
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I have found different values depending where is read.
I should like have a graphene sheet on copper to be used in a ionizer to generate lots of electrons
 
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  • #2
Javier Lopez said:
I have found different values depending where is read.
I should like have a graphene sheet on copper to be used in a ionizer to generate lots of electrons

It is because it depends on the growth method, the metallic substrate, and the physical environment of the graphene (in vacuum as opposed to exposing it in air), among other things. Either you find a reference that has the graphene sheet in the exact same situation as yours, or you make your own measurement of the work function of your graphene.

Zz.
 
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Likes Javier Lopez
  • #3
May be. Another think is graphene does not catch oxigen, so perhaps carbon oxide one (I think exist) is better
 
  • #4
Javier Lopez said:
May be. Another think is graphene does not catch oxigen, so perhaps carbon oxide one (I think exist) is better

Not exactly sure what you are talking about here.

Solar cells are PN photodiodes. The current is due to photogeneration. This is not THE standard photoelectric effect, which is the emission of photoelectron into vacuum.

Zz.
 
  • #5
I have in general a doubth about different surface related effects: photoelectric, thermal radiation and charge density in capacitors (and perhaps some others): all are proportional to surface area, but there are several surface increasing methods asanodizing or grow nanotubes that does not increases the effect directly proportional to new surface that can be dozens times, but perhaps reduces a few the emission coefficient.

The photoelectric effect is very interesting, because if you place 2 pallalel graphene plates and heat one using sun energy and mirrors to high temperatures you could have a low cost photoelectric cell using almost all the sun spectrum :)

J.L.
 

1. What is the work function of graphene sheets?

The work function of graphene sheets is a measure of the energy required to remove an electron from the surface of the material. It is typically expressed in electron volts (eV) and depends on factors such as the material's thickness, surface conditions, and temperature.

2. How does the work function of graphene sheets compare to other materials?

Graphene has a relatively low work function compared to other materials, making it a favorable choice for applications that require efficient electron emission. For example, its work function is approximately 4.5 eV, while that of copper is 4.7 eV and gold is 5.1 eV.

3. What factors affect the work function of graphene sheets?

The work function of graphene sheets can be influenced by factors such as the number of layers, defects in the crystal structure, and the presence of impurities on the surface. Additionally, the work function can be modified by applying an external electric field or doping the material with specific elements.

4. How is the work function of graphene sheets measured?

The work function of graphene sheets can be measured using various techniques, such as Kelvin probe force microscopy, ultraviolet photoelectron spectroscopy, and field emission microscopy. These methods involve applying an external electric field to measure the energy required to extract electrons from the material's surface.

5. What are the practical applications of understanding the work function of graphene sheets?

Understanding the work function of graphene sheets is crucial in various fields, including electronics, energy storage, and catalysis. For example, it can help in designing more efficient solar cells, field emission devices, and sensors. Additionally, it can aid in the development of better techniques for graphene synthesis and surface modification.

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