about 0.2 V
more at higher temps
any closer look at the specific diodes spec sheet
dopeants vary
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.
When the temperature increases, the barrier potential in a semiconductor diode decreases. This is due to the increase in carrier density at higher temperatures, which results in more charge carriers being available to pass through the barrier. Ultimately, this leads to a lower resistance across the diode and a decrease in the potential barrier.
germanium has great intrinsic concentration at room temperature,hence conduction is great in germanum compared to silicon, and resistance decreases in germanum and hence built in potentail also less in germanum compared to silicon.built in potential of silicon is 0.7v built in potential of germanum is 0.3v. 1)intrinsic concentration of germanium at room temperature is 2.5*10^13 atoms/cm^3. 2)intrinsic concentration of silicon at room temperature of 300k is 1.5*10^10 atoms/cm^3.
== When we make a semiconductor junction (a p-n junction), the electric fields force charges to shift creating what is called a depletion region. This depletion region forms a potential barrier across the junction. This potential barrier has a voltage associated with it, and that voltage is 0.3 volts (approximately) for germanium semiconductor material, and 0.7 volts (approximately) for silicon semiconductor. The terms we apply to this barrier potential are the built-in voltage (or potential), junction voltage (or potential), and contact potential. Use the link below to check facts and review some other closely related material.
A step potential is a sudden change in potential energy experienced by a particle when entering a different region with a different potential. This change can lead to reflection, transmission, and tunneling of the particle through the potential barrier. Step potentials are commonly used in quantum mechanics to study the behavior of particles encountering such barriers.
Potential barrier of silicon is 0.7, whereas potential barrier of germanium is 0.3
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.
The potential barrier of germanium is typically around 0.3 to 0.7 electron volts (eV) when used as a semiconductor in electronic devices. This barrier helps control the flow of current in the material and is crucial for its behavior as a semiconductor.
Silicon has a larger band gap than germanium, leading to a higher barrier potential. This is due to the differences in the electronic structure of these two materials. Silicon's larger band gap means that it requires more energy to move electrons across the junction, resulting in a higher barrier potential compared to germanium.
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.
When the temperature increases, the barrier potential in a semiconductor diode decreases. This is due to the increase in carrier density at higher temperatures, which results in more charge carriers being available to pass through the barrier. Ultimately, this leads to a lower resistance across the diode and a decrease in the potential barrier.
germanium has great intrinsic concentration at room temperature,hence conduction is great in germanum compared to silicon, and resistance decreases in germanum and hence built in potentail also less in germanum compared to silicon.built in potential of silicon is 0.7v built in potential of germanum is 0.3v. 1)intrinsic concentration of germanium at room temperature is 2.5*10^13 atoms/cm^3. 2)intrinsic concentration of silicon at room temperature of 300k is 1.5*10^10 atoms/cm^3.
== When we make a semiconductor junction (a p-n junction), the electric fields force charges to shift creating what is called a depletion region. This depletion region forms a potential barrier across the junction. This potential barrier has a voltage associated with it, and that voltage is 0.3 volts (approximately) for germanium semiconductor material, and 0.7 volts (approximately) for silicon semiconductor. The terms we apply to this barrier potential are the built-in voltage (or potential), junction voltage (or potential), and contact potential. Use the link below to check facts and review some other closely related material.
The forward voltage of a semiconductor junction, silicon or germanium, changes by -2mV for every rise in temperature of 1 degree C, so your friend is correct
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.
The potential across a pn junction is called potential barrier because majority charge carriers have to overcome this potential before crossing the junction.
Breakdown voltage is far greater than barrier potential. silicon:- break-down voltage :- 5v - 450 v barrier potential ;- 0.5v to 0.7 V