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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.
Solution
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,
Ec-EF=EG/2 = 0.56 eV
f(Ec)= 1/1+exp[0.56/86.25x 106x300]=3.9x 1010
Answer: Probability = 3. 9 X 1010
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