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Energy-Wavelength Equation:
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The fundamental relationship between photon energy and wavelength is described by the equation E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is wavelength. This equation is crucial for calculating band gap energy in semiconductors from absorption measurements.
The calculator uses the energy-wavelength equation:
Where:
Explanation: This equation converts wavelength measurements to energy values, which is particularly useful for determining semiconductor band gaps from optical absorption data.
Details: Accurate band gap energy calculation is essential for semiconductor characterization, optoelectronic device design, and materials research. It helps determine the electronic properties and potential applications of semiconductor materials.
Tips: Enter wavelength in meters. For nanometer values, divide by 10⁹ (1 nm = 10⁻⁹ m). The value must be greater than zero.
Q1: Why convert wavelength to energy for band gap measurements?
A: Optical absorption measurements typically provide wavelength data, but band gap is an energy property. This conversion allows direct determination of the energy band gap from absorption spectra.
Q2: What are typical band gap energy values?
A: Band gaps range from about 0.1 eV (narrow gap semiconductors) to 6 eV (wide band gap materials), corresponding to wavelengths from infrared to ultraviolet.
Q3: How accurate is this calculation?
A: The calculation is mathematically exact based on the fundamental constants. Accuracy depends on the precision of the wavelength measurement.
Q4: Can I use different units?
A: The calculator requires meters. Convert other units first: nanometers (÷10⁹), micrometers (÷10⁶), or angstroms (÷10¹⁰).
Q5: What about electronvolts instead of joules?
A: For eV results, divide the energy in joules by 1.602×10⁻¹⁹ (1 eV = 1.602×10⁻¹⁹ J). Many prefer eV as it's more convenient for band gap energies.