High School What is the work function of graphene sheets?

[Javier Lopez]

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

 

[ZapperZ]

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.

 

[Javier Lopez]

May be. Another think is graphene does not catch oxigen, so perhaps carbon oxide one (I think exist) is better

 

[ZapperZ]

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.

 

[Javier Lopez]

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.