Question on SemiConductors Depletion Layer

Sandy17sandy17 SG

I need help in understanding the various electrical components

MyPillowTalks SG

Hello, i have a little knowledge in electrical and electronics engineering.

Maybe can post your questions here so we can learn from each other together?

syncopation_music SG

hi , i grad from poly electronics engineering ,would like to know what is the thing you find difficult abt electrical component ?

Sandy17sandy17 SG

I don’t understand the capactitive effect in semiconductors

syncopation_music SG

semiconductor is a big thing .. which one you dont understand ?

you mean the transistor and field effect transistor as a whole or do you mean integrated circuit ?please help us by providing specific reference .Else i cant answer such a broad question . thanks

Uraniumfish SG

R u referring to capacitance in semiconductor diodes?

Sandy17sandy17 SG

The part where depletion width changes when the voltage across it is changed.

eagle SG

Hi,

you need to be more specific. You mentioned needing help in understanding various electrical components, but your question is based on the internal workings of a p-n junction.

Also, you will need to indicate which level you are asking at. This topic is covered in JC, poly and uni levels. JC syllabus touched on the depletion region, but does not touch on capacitance.

Finally, a capacitor acts like an infinite resistance to a d.c., but it is a short to a a.c.

Sandy17sandy17 SG

This is covered in electrical enginerring at the uni level. Let me rephrase the question.

eagle SG

Hi,

Are you sure that is the exact wording and phrase in your notes? Typically capacitive effects are not "equated" to resistive effects.

To my memory, the depletion region within the p-n junction acts as an infinite resistance to current flowing in one direction, and not the other, resulting it being like a diode.

Junction capacitance forms because of the charge variations throughout the depletion layer, since C = dQ/dV

I'm guessing that you are meaning the depletion layer functions as a resistor, while at the same time possessing a capacitive effect because of charge variations among the depletion layer.

Sandy17sandy17 SG

Thank you. I was confused with the two concepts　.