1. What is Band Gap Energy?

Band gap energy is the energy difference between the valence band and conduction band in a material. It determines the electrical and optical properties of semiconductors and insulators, influencing how they interact with light and conduct electricity.

2. How Does the Calculator Work?

The calculator uses the band gap energy equation:

Where:

• \( E \) — Band gap energy (eV)
• \( h \) — Planck's constant (4.135667662 × 10⁻¹⁵ eV·s)
• \( c \) — Speed of light (3 × 10⁸ m/s)
• \( \lambda \) — Wavelength (m)

Explanation: This equation converts the wavelength of light to the corresponding photon energy, which represents the minimum band gap energy required for electronic transitions in a material.

3. Importance of Band Gap Calculation

Details: Accurate band gap calculation is essential for semiconductor device design, solar cell development, LED technology, and understanding material properties for various electronic and optoelectronic applications.

4. Using the Calculator

Tips: Enter the wavelength in meters. The value must be positive and non-zero. For best results, use scientific notation for very small wavelengths typical in optical applications.

5. Frequently Asked Questions (FAQ)

Q1: What units should I use for wavelength?
A: The calculator requires wavelength input in meters (m). For nanometer inputs, divide by 10⁹ to convert to meters.

Q2: Why is band gap energy important?
A: Band gap determines whether a material is a conductor, semiconductor, or insulator, and affects its optical absorption and emission properties.

Q3: What are typical band gap values?
A: Silicon has ~1.1 eV, Germanium ~0.67 eV, while wide band gap materials like GaN can have 3.4 eV.

Q4: Can this calculator be used for all materials?
A: This calculates photon energy from wavelength. The actual band gap may differ slightly due to material-specific properties and measurement conditions.

Q5: How does temperature affect band gap?
A: Band gap typically decreases with increasing temperature due to lattice expansion and electron-phonon interactions.