Electronics - Diodes and Applications - Discussion

This is in response to WALEED and AMIT. It is true that the BARRIER potential (natural difference of potential between the p-type and the n-type sides of the junction) of Si is approximately 0.7V and that of Ge is approximately 0.3V.

Now, here we are talking about the TERMINAL potential (potentially applied to a p-n junction to obtain a desired mode of operation) which must be above the barrier potential (0.7) in order for the current to flow across the junction since the polarities are matched ie positive linked to the positive terminal.

The statement is incorrect. As silicon diodes get forward biased at 0.7 volt only. Not beyond this voltage. So it would act as open switch.

If the positive terminal is connected with other positive terminal or negative terminal is connected with other negative terminal it becomes an forward bias.

But you have written that PD above 0.7 v which is wrong it should be 0.7 v which is justifiable not above 0.7 v which is a wrong statement.

What are the applications of diode?

But in curve diode characteristics voltage drop in diode .3 and .7 and matching polarity means + to +.

What is mean by forward bias and reverse bias. And also explain characteristics curve of diode.

When forward biased, the volage drop across a silicon diode is 0.7V where as for a Germanium diode it's 0.3V.

Becuse diode has polirty is same so in forward diode act as close switch or lower resistance.

Matched polarity connection means positive to positive connection. So this is forward biased and also 0.7 voltage drop across the diode during this condition.