ONE FORMULA, ONE ANSWER
Photoelectric Stopping Voltage Calculator
Calculate the reverse voltage magnitude needed to stop the fastest photoelectrons in a single-photon model. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Stopping voltage magnitude V_stop
Enter values and select Calculate.
V_stop = (hc/λ − φ)/e, when hc/λ ≥ φ
Assumptions
Required: λ>0 and φ≥0. Supply the work function of the actual surface. Use monochromatic single-photon excitation. Excluded: multiphoton processes, thermionic emission, contact potentials and surface contamination. Below threshold the app reports no emission; at threshold V_stop=0. The result is a reverse-voltage magnitude and does not predict photocurrent or quantum efficiency.
Displayed values are floating-point approximations. Design safety factors and unprovided error contributions are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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