engineering recuitment ISRO Scientist Electronics Mock Test Electronic Devices Carrier Transport Carrier Diffusion
At room temperature, the n-type Si sample is illustrated below as ohmic contact on one end and a reflecting boundary on the other. It is doped with ND = 5 × 1016 cm-3. \(\rm μ _e= 1600 \frac{cm^2}{V-sec} , μ _h = 600 \frac{cm^2}{V-sec} \) and the minority carrier diffusion length is 50μm.
This sample is excited with constant, low-level illumination creating the excess minority carrier profile below
Total hole current density Jh(x) is
1
\(\rm 4.8 \times 10^{-5} \left[ u(x) - u(x - 5 \times 10^{-4}) \right] \ \frac{A}{cm^2}\)
2
\(\rm -4.8 \times 10^{-5} \left[ u(x) - u(x - 5 \times 10^{-4}) \right] \ \frac{A}{cm^2}\)
3
\(\rm 1.2 \times 10^{-5} \left[ u(x) \right] \ \frac{A}{cm^2}\)
4
\(\rm -1.2 \times 10^{-5} \left[ u(x) \right] \ \frac{A}{cm^2}\)