Please show all steps and work with explanations Problem 4 A

Please show all steps and work with explanations!

Problem 4 A step junction has NA-1017 ND 5x101 incm3, with Dm 30 DD-12 cm2/s. Let n 10 cm 3, kT 0.026 eV, La 10-3 L 1.5x103 cm. and the area A-104 cm Calculate the ratio of the hole current to the total current in the depletion region. Does it make sense? Explain.

Solution

in depletion region total current is due to electron difflusion and hole difflusion

but at equilibrium hole difflusion and electron difflusion should be equal and they produce equal amount of current

with opposite direction

hence total current is zero hence ratio becomes infinite