Breakdown voltage is far greater than barrier potential.
silicon:-
break-down voltage :- 5v - 450 v
barrier potential ;- 0.5v to 0.7 V
forward breakover voltage is slightly smaller than reverse breakdown voltage
there is no forward breakdown voltage for any diode
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 critical value of the voltage, at which the breakdown of a P-N junction diode occurs is called the breakdown voltage.The breakdown voltage depends on the width of the depletion region, which, in turn, depends on the doping level. The junction offers almost zero resistance at the breakdown point.
The integration of the electric field across the depletion region is what develops the barrier voltage.
The breakdown voltage is greater than the barrier potential because it represents the voltage at which a significant increase in current occurs due to the breakdown of the insulating properties of a material, such as a diode or semiconductor junction. While the barrier potential is the voltage required to overcome the energy barrier for charge carriers to cross the junction, breakdown voltage indicates the point at which the electric field becomes strong enough to ionize atoms or create charge carriers, leading to a dramatic increase in conduction. Thus, the breakdown voltage must exceed the barrier potential to initiate this avalanche of charge carriers.
One voltage is greater in thyristor whether forward breakover or reverse breakdown voltage. The greater of the two voltages in thyristor is forward breakover voltage.
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.
It is stated that one of the voltage is greater in thyristor whether it be forward breakover or reverse breakdown voltage. It is also stated that the greater of the 2 voltages in thyristor is the forward breakover voltage.
forward breakover voltage is slightly smaller than reverse breakdown voltage
Voltage is a measure of the electric potential energy difference between two points in an electric field. The greater the voltage, the greater the electric potential energy difference between the two points.
The typical value of the barrier potential for a germanium diode is around 0.3 to 0.4 volts. This barrier potential is the voltage required to overcome the potential barrier at the junction of the diode and allow current flow in the forward direction.
There is no such thing as a 'voltage difference'! 'Voltage' means 'potential difference', so what you appear to be asking is "How do you get the largest potential difference difference?'! Potential difference is caused by the separation of charges between two points. The greater the amount of charge separation, the greater the potential difference.
A normal diode with reverse voltage in excess of its rated breakdown voltage could fail. Resistance could be high (blown open) or low (shorted).
In this circumstance, the clearance between components at different potential must be increased.
Cut in voltage is the minimum voltage required to overcome the barrier potential. In other words it is like trying to push a large boulder....it may not be possible to push a large boulder by one person but it may be done if 2 or more people try to push it together depending on the size of the boulder.....similarly....the charge carriers in the barrier region have a potential energy of about 0.6V for Silicon and about 0.2V for Germanium. so in order for the diode to conduct, it is required to overcome the potential of the charge carriers in the junction barrier region and hence only if a potential more than that of the barrier potential (cut off voltage) is applied, then electrons flow past the junction barrier and the diode conducts.
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.