(a) An extrinsic n-type si sample is 3 mm long and has a cross sectio…
Previous year question for Basic Electronics Engineering.
Question
(a) An extrinsic n-type si sample is 3 mm long and has a cross section of $5 \times 10^{-9}\text{ m}^2$. The donar concentration at $300^\circ\text{K}$ is $5 \times 10^{14}/\text{cm}^3$ and corresponds to 1 impurity per $10^8\text{ si}$ atoms. A steady current of $2\text{ }\mu\text{A}$ exists in the bar. Determine the electron and hole concentration, the conductivity and the voltage across the bar. Use $n_e = 1.45 \times 10^{10}/\text{cm}^3$ and $\mu_n = 1500\text{ cm}^2/\text{v.s.}$ for si.
(b) What is the difference between diffusion and drift current? A semiconductor extrensic material has role and electrons concentrations of p and n respectively. What is the total diffusion and drift current?
- Year: 2022
- Subject: Basic Electronics Engineering