Tunnel diode characteristics
a)It is also capable for very fast operations. b)It has heavily doped PN junction of only 10 nm wide . c)It exhibit negative resistance region. d) Applications:microwave applications, ultra high speed switching device,relaxation oscillators. e)The process of penetrating charge carrier directly through potential barrier is called tunneling.
Symbol of TUNNEL DIODE
operating principle of tunnel diode
Working
The operation of tunnel diode is based on special characteristics known as negative resistance. The width of the depletion region is inversely proportional to the square root of impurity concentration. So increase in the impurity concentration, the depletion region width will reduce. The thickness of depletion region of this diode is so small. That indicates there is large probability of an electron can penetrate through this barrier. This behavior is called is tunneling & hence the name of the high impurity density PN junction is called as tunnel diode.