GATE EC 2018 Set 1 — Question 28
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Electronic Devices → P-N Junction & Diodes → Junction Formation & Depletion
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Question
A p-n step junction diode with a contact potential of 0.65 V has a depletion width of 1 m at equilibrium. The forward voltage (in volts, correct to two decimal places) at which this width reduces to 0.6 m is _______.
Correct answer
0.4 to 0.43
Solution
For a p-n step junction, the depletion width is given by:
This implies .At equilibrium ():
,
--- (1)At forward voltage :
--- (2)Dividing (2) by (1):
Rounding to two decimal places, the forward voltage is 0.42 V.
This implies .At equilibrium ():
,
--- (1)At forward voltage :
--- (2)Dividing (2) by (1):
Rounding to two decimal places, the forward voltage is 0.42 V.
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