Threshold Frequency & Work Function

Introduction

• Understanding the concepts of threshold frequency and work function is essential in explaining the phenomenon of photoemission.

Threshold Frequency

• The threshold frequency ($ν_0$) is the minimum frequency of light or electromagnetic radiation required to cause photoemission.
• It is the specific frequency at which photoemission begins for a given material.
• If the frequency of the incoming light is below the threshold frequency, no photoemission occurs.

Work Function

• The work function ($Φ$) represents the minimum energy required to remove an electron from the surface of a metal.
• It is essentially the energy barrier that must be overcome to release an electron from the metal.
• The work function is typically measured in electronvolts (eV).

Mathematical Relationship

• The threshold frequency and the work function are related by the following equation:
• $ν_0 = Φ / h$
• Where:
  • $ν_0$ is the threshold frequency.
  • $Φ$ is the work function.
  • h is Planck's constant.

Variation Among Metals

• Different metals have different work functions.
• This means that it is easier to remove electrons from some metals compared to others.
• Consequently, the minimum frequency of photons needed to induce photoemission can vary from one metal to another.

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Threshold Frequency & Work Function

Summary

• The threshold frequency is the minimum frequency of incoming radiation required to initiate photoemission.
• The work function represents the minimum energy required to release an electron from a metal's surface.
• The relationship between threshold frequency and work function is given by the equation $ν_0 = Φ / h$, where h is Planck's constant.