GATE EC 2015 Set 2 — Question 20
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Electronic Devices → Carrier Transport → Mobility, Resistivity & Conductivity
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Question
A piece of silicon is doped uniformly with phosphorous with a doping concentration of . The expected value of mobility versus doping concentration for silicon assuming full dopant ionization is shown below. The charge of an electron is . The conductivity (in ) of the silicon sample at is ______.
Correct answer
1.8 to 2
Solution
1.Determine Carrier Concentration: Phosphorous is a donor impurity. For a doping concentration with full ionization, the electron concentration .
2.Find Mobility from Graph: From the provided graph, at a doping concentration of , the electron mobility is approximately .
3.Calculate Conductivity: Conductivity is calculated as:
The value falls within the specified range of 1.8 to 2.0.Continue learning with Success Tracker
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