Question

What is the probability of an electron being thermally excited to conduction
band in Si at 27cC.The band gap energy is 1.12 eV.

Answer 1

Data : T =27°C=300K,      Eg= 1.12eV

K = 1.38 x 10²³ J/K = 86.25 x 10²⁶ eV/K
Formula:  f{Ec) = 1/1 +e^{(Ec-Et) /kT}

Calculations:  Since an intrinsic semiconductor. Hence,
E_c-E_F=E_G/2 = 0.56 eV
f(Ec)= 1/1+exp[0.56/86.25x 10⁶x300]=3.9x 10¹⁰

Answer:    Probability = 3. 9 X 10¹⁰