Photon Semiconductor Interactions
1. In semiconductors, what condition must a photon satisfy to generate an electron-hole pair?
2. Which type of material is more efficient for light emission in LEDs?
3. Fluorescence differs from phosphorescence mainly in:
4. For a semiconductor with Eg = 1.9 eV, find the maximum wavelength λmax of photons that can generate e-h pairs. Use h = 6.626×10⁻³⁴ J·s, c = 3×10⁸ m/s, q = 1.6×10⁻¹⁹ C.
5. The absorption coefficient α of a direct bandgap semiconductor near the band edge follows which relation?
6. In a semiconductor laser, population inversion is achieved when:
7. A semiconductor has Eg = 2.0 eV. If a photon of λ = 700 nm strikes it, will it create an e-h pair? Use hc = 1240 eV·nm.
8. The rate of spontaneous emission Rsp in a direct bandgap semiconductor is proportional to:
9. In stimulated emission, the emitted photon has: