Help on KE of photoelectron emmision

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In summary, the conversation discusses the effects of a 180nm wavelength light on an aluminium surface with a work function of 4.2eV. The main question is what is the kinetic energy of the fastest and slowest emitted photoelectrons, as well as the cutoff wavelength for the aluminium. The equation KE max = hf - W is used to determine the maximum kinetic energy, and the threshold frequency is used to calculate the cutoff wavelength. Similarly, for the minimum kinetic energy, the threshold frequency is used.
  • #1
carus88
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'light of wavelength 180nm falls on an aluminium surface. the work funct is 4.2eV.
what is the KE of the fastest and slowest emmited photoelectrons?
Also the cutoff wavelength for the Aluminium?
i only need the right equations an a little guidance as i myt as well be a complete novice.

i have worked out what i think is the max KE as 2.69eV

using KE max = hf - W (w as the work funct)
 
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  • #2
The second part asks for kinetic energy of the slowest emitted electrons. What do you imagine is the slowest speed an electron can be emitted? The cutoff wavelength is just that wavelength that provides the same energy of the work function.
 
  • #3
so i use the work funct equation an work backwards to get the threshold freq an then the cut off wavelength?

and for the min KE use the threshold freq?
 
  • #4
exactly! :smile:
 
  • #5
thank you so much!
 

1. What is the kinetic energy of photoelectron emission?

The kinetic energy of photoelectron emission is the amount of energy that a photoelectron carries after it is emitted from a material due to the absorption of a photon. This energy is dependent on the energy of the absorbed photon and the binding energy of the electron in the material.

2. How is the kinetic energy of photoelectron emission calculated?

The kinetic energy of photoelectron emission can be calculated using the equation KE = hν - BE, where KE is the kinetic energy, h is Planck's constant, ν is the frequency of the absorbed photon, and BE is the binding energy of the electron in the material.

3. What factors affect the kinetic energy of photoelectron emission?

The kinetic energy of photoelectron emission can be affected by the energy of the absorbed photon, the binding energy of the electron in the material, and the angle and direction of the emitted electron's path. Other factors such as the material's surface and the intensity of the incident light can also play a role.

4. How does the kinetic energy of photoelectron emission contribute to understanding the properties of materials?

The kinetic energy of photoelectron emission can provide valuable information about the electronic structure and properties of materials. By analyzing the energy distribution of emitted electrons, scientists can determine the energy levels and band structure of the material, as well as its chemical composition and surface properties.

5. Can the kinetic energy of photoelectron emission be controlled or manipulated?

Yes, the kinetic energy of photoelectron emission can be controlled by adjusting the energy of the incident light or by changing the properties of the material. This can be useful in applications such as surface analysis, where scientists can control the energy of emitted electrons to study specific layers or regions of a material.

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