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Why TUNNEL diode have negative resistance?

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Naveed Alam

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equivalent circuit of a tunnel diode

Dear All,
If you see TUNNEL diode characteristic curve, you will see that after large currents initially, current reduces till 0.6 volt (almost). and then obey normal diode characteristic. From high currents till 0.6 volt (valley point) there is a negative resistance area.
Q. why is this negative resistance area.
Q2. if due to construction, then please give some details.

References will be highly appreciated.
 

tunnel diode details

Hi Naveed,

Here is one link that can help https://en.wikipedia.org/wiki/Negative_resistance the other will be just search tunnel diode and you will see why there is a negative resistance region. Its actually negative differential resistance, this is when the current decreases with the increase of voltage. You might also want to look up Quantum tunneling, hope it helps.
 

sreevyas said:
btw are u looking the energy band level details then get back to me,
Click to expand...

I want the actual reason of the -ve resistance in tunnel diode. I know the equivalent circuit already, but I want to know what actually happen that in -ve resistance area by increasing voltage current decreases.. (there might be holes, electrons and ions doing something, but what? i want it to know)


Naveed
 

Naveed Alam said:
sreevyas said:
btw are u looking the energy band level details then get back to me,
Click to expand...

I want the actual reason of the -ve resistance in tunnel diode. I know the equivalent circuit already, but I want to know what actually happen that in -ve resistance area by increasing voltage current decreases.. (there might be holes, electrons and ions doing something, but what? i want it to know

Naveed
Click to expand...

Do you know, why this kind of diode was called "tunnel" diode ?
Answer: Because one could observe this effect but had really no explanation. As a consequence, one concluded that electrons "somehow" are able to find a tunnel-like path to move through the device before it "opened the door" above the treshold voltage. Lateron the effect was physically justified by ESAKI (therefore the name "Esaki"-Diode) - but at present I am not able to repeat his explanations. Does this help a bit ?
Regards
 

but the -ve resistance is still mystery?.. i think there should be definitely some answer to this.



Naveed
 

do u have idea about the conduction band daigram in momentum space.
there electron jumps to next vaelly there due momentum variation the resistance will become negative. in this direction if it make any sense i'll get back to you will full details, wait couple of days, becaz i'm busy in my work, i read long back. to explain you i need to refer once again

__sree
 

sreevyas said:
do u have idea about the conduction band daigram in momentum space.
there electron jumps to next vaelly there due momentum variation the resistance will become negative. in this direction if it make any sense i'll get back to you will full details, wait couple of days, becaz i'm busy in my work, i read long back. to explain you i need to refer once again

__sree
Click to expand...
Sree, if u explain it, it might be helpful for me.
 

go out to wikipedia,u may get detail
 

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