The voltage across a forward-biased PN junction in a semiconductor diode or transistor.
The integration of the electric field across the depletion region is what develops the barrier voltage.
Breakdown voltage is far greater than barrier potential. silicon:- break-down voltage :- 5v - 450 v barrier potential ;- 0.5v to 0.7 V
The barrier voltage of a diode is 0.7v for silicon and 0.3 for germanium. after this voltage is reached the current starts increasing rapidly... till this voltage is reached the current increases in very small steps...
ginago
No, we don not consider the barrier voltage of a diode to be able to act as a voltage source. The barrier voltage arises during construction of the p-n junction, and it results from charge separation. Separating charges results in voltage, but this difference of potential cannot be tapped as a voltage source because it cannot supply current the way we understand conventional voltage sources are able do.
The integration of the electric field across the depletion region is what develops the barrier voltage.
Breakdown voltage is far greater than barrier potential. silicon:- break-down voltage :- 5v - 450 v barrier potential ;- 0.5v to 0.7 V
The potential barrier of a diode is caused by the movement of electrons to create holes. The electrons and holes create a potential barrier, but as this voltage will not supply current, it cannot be used as a voltage source.
The barrier voltage of a diode is 0.7v for silicon and 0.3 for germanium. after this voltage is reached the current starts increasing rapidly... till this voltage is reached the current increases in very small steps...
0.7
ginago
No, we don not consider the barrier voltage of a diode to be able to act as a voltage source. The barrier voltage arises during construction of the p-n junction, and it results from charge separation. Separating charges results in voltage, but this difference of potential cannot be tapped as a voltage source because it cannot supply current the way we understand conventional voltage sources are able do.
When sufficient forward voltage is applied across the junction, the electric field opposing the further diffusion of electrons from n-type to p-type semiconductor gets lost. The electric field created due to the application of the forward voltage opposes that of the barrier potential and finally vanishes the barrier completely.
(A) The bias battery voltage (B) 0V (C) the diode barrier potentiaol (D) The total circuit voltage
zener cut in voltage
cut in voltage *** for silicon is 0.7volts and that for germanium is 0.3volts.According to Millman and Taub, "Pulse, Digital and Switching Waveforms", McGraw-Hill 1965, the cutin (or offset, break-point or threshold) voltage for a silicon diode is 0.6, and 0.2 for germanium.Breakdown voltage is another thing entirely. It is the reverse voltage at which the junction will break down.
In a purely classical world, the probability of a moving particle getting through an electro-static barrier was simple: if the kinetic energy of the particle was greater than the charge times the voltage, it was 100% likely to get through, if the KE was less, the probability was zero. In the latter case, the ball would simply bounce back, because the energy level of the voltage barrier ( 'E(vb)' ) was simply too large for that particle's KE to overcome When you do the mathematics of the Schroendinger Equation with this situation -- a charged particle meeting a voltage barrier -- you can no longer talk about what WILL happen with 100% certainty. You can only discuss the PROBABILITY of something happening. For example, even if the electron has more KE than E(bv), then there is some chance that it will bounce back. When a moving electron meets a voltage barrier, in which the initial KE is smaller than E(vb), then the probability of finding that electron in that barrier goes down fairly rapidly. If the barrier is thick, then the probability of finding the electron in that area of high voltage goes down to zero. On the other hand, it CAN happen that, for a thin barrier (or a fast electron or a voltage barrier not too large), that the probability of finding an electron beyond the barrier does NOT go down to zero. In that case, you have quantum tunnelling. The mathematics are fairly complicated; but have been shown to agree with experiment.