Does the diode ideality factor can be lesser than 1? or very close to 1?
ID and VD are the diode current and voltage, respectively
q is the charge on the electron
n is the ideality factor
k is Boltzmann’s constant
T is temperature in Kelvin
2
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\$\begingroup\$ Where did the equation come from? What are D, S, q, VD, n, k and T? \$\endgroup\$– TransistorAug 6, 2018 at 13:41
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1\$\begingroup\$ @Transistor Looks like the Shockley Diode Equation... or was that something you wanted the OG to figure out? Lol woops \$\endgroup\$– user103380Aug 6, 2018 at 14:18
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1 Answer
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The ideality factor adjusts the original Shockley diode equation to fit non-Germanium diodes more closely. There's also a series resistance term.
Equation 3.13 from the original 1950 paper from Bell System Technical Journal:
The factor was added a few years later in a fascinating paper on radioactive p-n junction power sources.
With silicon diodes the ideality factor is closer to 2 than 1. It can be higher than 2. A diode-connected silicon transistor operated at reasonable currents has an ideality factor close to 1.
I don't think it is ever less than 1 for a real diode, but that may not be correct.
answered Aug 6, 2018 at 15:00