Tunnel Diode
Definition :-
Forword विभव (potential)बढ़ाने पर n to p tunneling धारा मान बढ़ ता है एवं उच्चतम धारा प्राप्त होने के बाद धारा का मान घटता है। एवं फिर एकाएक धारा का मान बढ़ता जाता है। प्राप्त उच्च धारा को peak धारा (Ip) एवं विभव को peak विभव (Vp) कहते है। Tunnel diode कहलाता है।P-N Diode
Definition :-
डायोड एक P टाइप सेमीकंडक्टर और N टाइप सेमीकंडक्टर का जंक्शन होता है इसलिए डायोड को हम P-N जंक्शन डायोड भी कहते हैं।
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Tunnel
Diode |
P-N Diode |
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Preferred semiconductos used are Ge and GaAs |
Preferred semiconductors used are Ge and Si |
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Tunnelling current consists of majority carriers(i.e. electrons from
n-side to p-side) |
Current consists of minority carriers (i.e. holes from p-side to
n-side) |
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Low noise device |
Moderate noise device |
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Doping levels at p and n sides are very high |
Doping is normal in both p and n sides |
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At a small value of reverse voltage, a large current flows due to large the overlap between conduction band and valance band. It is useful as a frequency
converter |
leakage Current is extremely small up to certain reverse bias voltage.
Increases abruptly to extremely high at breakdown voltage. |
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It has negative resistance characteristics. Hence it is useful for reflection
amplifiers and oscillators. |
It does not have negative resistance and hence used as detector and RF
mixers. |
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The majority carrier (current) responds much faster to voltage changes.
This is suitable for microwave applications. |
The majority carrier (current) does not respond so fast to voltage changes. This is suitable for low-frequency applications only. |
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