I am trying to get an estimation the junction capacitance of my GaAs Photodiode with respect to varying bias voltages.(adsbygoogle = window.adsbygoogle || []).push({});

My Semiconductor Physics online textbook gives the following equations

with

ε_{0}= permittivity of free space

ε_{GgAs}= GaAs dielectric constant

μ = Mobility of electrons

ρ = resitivity

V_{bi}= built-in voltage

V_{A}= Bias voltage (in my case 0 - 5V)

A = photodiode area (in my case 0.3μm^{2})

Whenever, I work through the calculations I get answers that are many orders of magnitude off what I expect

I think the main issue is just getting the correct values(in the correct units) for each of the variables as I have been pulling them in from different sources.

Any help would appreciated.

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# Junction Capacitance in a GaAs Photodiode

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