2.20) An electron in free space is described by a plane wave given by where k = 1.5 x 109 m-1 and .

a) Determine the phase velocity of the plane wave. b) Calculate the wavelength, momentum, and kinetic energy (in eV) of the electron. Jawab: a) Mencari nilai Maka,

Keterangan: diturunkan menjadi 0

b) Mencari nilai 1. Mencari nilai Diketahui: Maka,

2. Mencari nilai

3. Mencari nilai Diketahui:

Maka,

6.4) (a) A sample of semiconductor has a cross-sectional area of 1 cm2 and a thickness of 0.1 cm. Determine the number of electron-hole pairs that are generated per unit volume per unit time by the uniform absorption of I watt of light at a wavelength of 6300 A. Assume each photon creates one electron-hole pair. (b) If the excess minority carrier lifetime is I0 hrs, what is the steady-state excess carrier concentration? Jawab:a)

diketahui

maka :

kemudian :

b) mencari konsentrasi steady state excess carrier