If temperature increases the generation of minority charge carriers increases. Hence, the reverse current
increases with the increase in temperature
. … Hence, the reverse saturation current in the germanium diodes is greater than the silicon diodes.
What is the reason for reverse saturation current?
The reverse saturation current is the part of the reverse current in a semiconductor diode which is caused by
the diffusion of minority carriers from the neutral regions to the depletion region
.
Why is the reverse saturation current small in silicon than in germanium diode?
The
silicon diode is less sensitive than
the germanium diode, hence the operation of silicon diodes is stable with changes in temperature. The Si diode has low reverse current compared to Ge.
What is reverse saturation current in germanium diode?
The reverse saturation current of a Germanium diode is of
the orders of micro-amperes (μA)
. … Forward Bias: When the p-type side of the diode is connected to a higher potential than the n-type side, the diode is said to be forward-biased, because it enhances the capability of the diode to conduct forward current.
What is the effect on the reverse saturation current of an increase in temperature on germanium diode?
Reverse saturation current (IS) of diode increases with increase in the temperature the rise is 7%/oC for both germanium and silicon and
approximately doubles for every 10oC rise in temperature
. Thus if we kept the voltage constant, as we increase temperature the current increases.
Is zener a diode?
A Zener diode is
a silicon semiconductor device that permits current to flow in
either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
What does saturation current depend on?
The saturation current depends on
the intensity of the light,for a given frequency
. More photons correspond to more electrons. One photon knock out one electron and if you increase the number of photons (or increase the intensity) you increase the current.
Why is Si preferred over GE?
The structure of Germanium crystals
will be destroyed at higher temperature
. However, Silicon crystals are not easily damaged by excess heat. Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes. Si is less expensive due to the greater abundance of element.
How do you calculate reverse saturation current?
Hint: We know that the current that flows in reverse bias PN junction diode is called reverse saturation current. From the diode current equation
I=Is(eVηVT−1)
the current should decrease as the temperature is increased but the opposite happens.
Is a diode a semiconductor?
A diode is
a semiconductor device
that essentially acts as a one-way switch for current. It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction. … When a diode allows current flow, it is forward-biased.
Which of the factors doesn’t change the diode current?
Which of the factors doesn’t change the diode current. Explanation:
I = Io [e
( v / nVt )
-1]
, as shown in this equation the diode current is dependent on temperature , voltage applied on the diode , Boltzmann’s constant but diode current is not dependent on resistance as it is independent of resistance.
What are the two types of breakdown in Zener diode?
A zener diode has two distinctly different breakdown mechanisms:
zener breakdown and avalanche breakdown
. The zener breakdown voltage decreases as the temperature increases, creating a negative temperature coefficient (TC).
What is reverse saturation current?
The saturation current (or scale current), more accurately the reverse saturation current, is
that part of the reverse current in a semiconductor diode caused by diffusion of minority carriers from the neutral regions to the depletion region
. This current is almost independent of the reverse voltage. (
Why does reverse saturation current increase with temperature?
The reverse saturation current is almost independent of the applied reverse bias voltage, but increases with the
rise of temperature of the junction diode
. This is because the minority carrier density contributing proportion increases with the rise of temperature.
Why does diode current increase with temperature?
An increased temperature will result in
a large number of broken covalent bonds increasing the large number of majority and minority carriers
. This amounts to a diode current larger than its previous diode current.
How does temperature affect diode?
Increasing the temperature
makes the diode to “turn ON” at lower voltages. The diode law for silicon – current changes with voltage and temperature. For a given current, the curve shifts by approximately 2 mV/°C. The light blue curve shows the effect on the IV curve if I
0
does not change with temperature.
