A silicon bar is doped with donor impurities ND = 2.25 × 1015 atoms/cm3. Given the intrinsic carrier concentration of silicon at T = 300 K is 1.5 × 1010/cm3. Assuming complete impurity ionization, the equilibrium electron and hole concentrations are respectively

Calculate the approximate wavelength (λ) of radiation emitted by an LED made of a semiconductor material with a band gap energy of 3.2 eV. (Take hc ≈ 1240 eV·nm or 12400 eV·Å)

In a semiconductor material, an electron's effective mass (m) is 0.067 times the free electron mass (me ≈ 9.11 × 10-31 kg). If the electron is subjected to a force of 2 × 10-19 N, what will be its acceleration?