6. Asample of intrinsic GaN (E, = 3.4 eV) is illuminated with a 10 mW/cm? beam of light at the wavelength of 300 nm. The electron lifetime is 2 ps. The electron and hole mobilities for intrinsic GaN are about 400 and 100 cm?/Vs, respectively. d. b. What is the number of photons arriving at the semiconductor surface (1 cm?) per second? Will the photons at this energy be absorbed? Assuming the GaN sample is 1 mm thick, and every photon is absorbed and creates an electron-hole pair, what is the optical generation rate? What is the excess carrier concentration when the light is on? Assume n; = 1.9x10-'9 cm?3 at room temperature, what is the recombination rate when the light is off? Calculate it again when the light is on. When the light is on, what are the steady-state carrier densities n and p? What is the conductivity of this sample in dark environment? Calculate it again when the light is on