107 777
Assignments Done
100%
Successfully Done
In July 2024

# Answer to Question #109529 in Electrical Engineering for Bharti

Question #109529
Given a forward biased si diode with I = 1mA. If the diffusion capacitance is Cd =1microferad , what is the diffusion Length Lp? Assume that the doping of the P-side is much greater than that of the n-side . Use Dp = 13metersquare second.
1
2020-04-19T07:39:46-0400

In this problem, we will need the following:

"L_p" - diffusion length for holes, m;

"D_p" - diffusion constant for holes, "\\text{m}^2\/\\text{s}";

"C_D" - diffusion capacitance, μF;

"\\tau_p" - meal life time for holes, s;

"V_T" - volt equivalent of temperature "T" (26 mV for 300 K);

"\\eta=1" for Ge and "\\eta=2" for SI - a constant, "\\eta=I_0(e^{V\/\\eta V_T}-1)."

The diffusion length is

"L_p=(D_p\\tau_p)^{1\/2}.\\\\\n\\space\\\\\nC_D=\\frac{\\tau_p I}{\\eta V_T},\\\\\n\\space\\\\\nV_T=\\frac{T}{11600.}"

Therefore, combining all this, we get

"L_P=\\sqrt{\\frac{D_pC_D\\eta V_T}{I}}=\\\\ \\space\\\\\n=\\sqrt{\\frac{13\\cdot(1\\cdot10^{-6})\\cdot2\\cdot(300\/11600)}{(1\\cdot10^{-3})}}=0.0259\\text{ m}."

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!