Photoelectric Effect Calculator

Calculate electron emission from materials using Einstein's photoelectric equation and quantum mechanics

Calculate Photoelectric Effect

Properties of incident electromagnetic radiation

Minimum energy to remove an electron from the material

Photoelectric Effect Results

Photoelectric Effect Does Not Occur

Photon frequency below threshold frequency

0.000
Max Kinetic Energy (eV)
0.000
Stopping Potential (V)
0.000
Max Velocity (×10⁶ m/s)
0.000
Photon Energy (eV)

Incident Photon Properties

Frequency: 0.000 THz

Wavelength: 0.0 nm

Energy: 0.000 eV

Material Properties

Work Function: 0.00 eV

Threshold Frequency: 0.000 THz

Threshold Wavelength: 0.0 nm

Einstein's Equation: Kmax = hf - Φ = 0.000 - 0.00 = 0.000 eV

Condition: Photoelectric effect occurs when f > f₀ (0.000 THz 0.000 THz)

Analysis

❌ No photoelectric effect - photon energy (0.000 eV) is below work function (0.00 eV).

Example Calculation

Sodium Photoelectric Cell

Material: Sodium (Na)

Work Function (Φ): 2.75 eV

Incident Light: Blue light at 450 nm wavelength

Photon Energy: E = hc/λ = 2.76 eV

Calculation Steps

1. Calculate photon energy: E = hc/λ = 2.76 eV

2. Check condition: E > Φ → 2.76 eV > 2.75 eV ✓

3. Maximum kinetic energy: Kmax = E - Φ = 2.76 - 2.75 = 0.01 eV

Result: Photoelectric effect occurs with very low electron energies

Physics Constants

Planck constant (h)6.626 × 10⁻³⁴ J⋅s
Speed of light (c)2.998 × 10⁸ m/s
Electron charge (e)1.602 × 10⁻¹⁹ C
Electron mass (mₑ)9.109 × 10⁻³¹ kg

Common Work Functions

Cesium2.1 eV
Potassium2.3 eV
Sodium2.75 eV
Aluminum4.28 eV
Copper4.7 eV
Gold5.1 eV

Key Concepts

Einstein's equation: Kmax = hf - Φ

Effect only occurs when f > f₀ (threshold frequency)

Kinetic energy depends on frequency, not intensity

Work function is material-specific property

Understanding the Photoelectric Effect

What is the Photoelectric Effect?

The photoelectric effect is a quantum phenomenon where electrons are emitted from the surface of a material when light of sufficient frequency strikes it. Einstein explained this effect in 1905, earning him the Nobel Prize in Physics in 1921.

Key Principles

  • Light consists of discrete packets of energy called photons
  • Each photon carries energy E = hf
  • Electrons need minimum energy (work function) to escape
  • Excess energy becomes kinetic energy of the electron

Einstein's Photoelectric Equation

Kmax = hf - Φ

  • Kmax: Maximum kinetic energy of emitted electrons
  • h: Planck's constant (6.626 × 10⁻³⁴ J⋅s)
  • f: Frequency of incident light
  • Φ: Work function of the material

Note: The photoelectric effect demonstrates the particle nature of light and was crucial evidence for quantum mechanics.

Applications of the Photoelectric Effect

Photomultiplier Tubes

Used in scientific instruments to detect and amplify weak light signals by converting photons to electrons.

Solar Cells

Convert sunlight directly into electrical energy using the photoelectric effect in semiconductor materials.

Image Sensors

Digital cameras and photodiodes use the photoelectric effect to convert light into electrical signals for image capture.