Question

In: Electrical Engineering

Explain the Schottky barrier lowering and its effect on the reverse saturation current in a Schottky...

Explain the Schottky barrier lowering and its effect on the reverse saturation current in a Schottky barrier diode.

Solutions

Expert Solution

Schottky diode :

Metals have electrons as majority carrier, and N-type semiconductor also possesses electrons as majority charge carrier. Thus, when a metal-semiconductor junction is unbiased, then current doesn’t flow in a diode. This is because electrons in N-type region do not possess sufficient energy to transit from N-type junction to metal. But when the junction is forward biased then electrons acquire energy to cross the barrier.

This barrier is called Schottky Barrier. The electrons which are moving from N-type to metals are termed as hot carriers. They are called so because when the junction is forward biased electrons acquire a significant amount of energy. And they enter metal junction with this high magnitude of energy. That’s why diode is also called hot-carrier diode.

The best thing about Schottky diode is its fast switching ability. There is no role of the depletion layer in the case of Schottky diode, that’s the reason it possesses fast switching than P-N Junction diode. Metals and N-type semiconductor have electrons as majority charge carriers.Thus, the entire current is due to bulk carriers. There are no holes, so there is no depletion layer. Thus, there is no charge storage at the junction.

Due to the absence of charge storage, the Schottky diode can be easily switched from forward biased to reverse biased. A p-n junction is bipolar because it consists of both electrons as well as holes as majority carriers, but Schottky diode is unipolar because it involves only one charge carrier i.e. electron.

The barrier potential of Schottky diode lies in the range of 0.2-0.25V which is much lower than the barrier potential of Silicon 0.7 V. The reason behind this low barrier potential is, again the absence of depletion layer.

Thus, no significant current flows from metal to semiconductor when the diode is reverse biased. Thus, the current flows only in the case of forward biased of the metal-semiconductor junction.


Related Solutions

Describe the charge flow in a forward-biased Schottky barrier diode
Describe the charge flow in a forward-biased Schottky barrier diode
Analyze the current process of reverse migration in India during the pandemic and its impact in...
Analyze the current process of reverse migration in India during the pandemic and its impact in India’s development process in the future. Do you think it’s going to sustain? Analyze the situation in the context of the conceptual framework and give contradictions if any. Also give some policy suggestions to the problem of rural-urban migration in Indian context. IN DETAIL ANSWER ITS FOR 15 marks NO hand written answer please
Calculate ΔrG○ at 298 K for these reactions and predict the effect on ΔrG○ of lowering...
Calculate ΔrG○ at 298 K for these reactions and predict the effect on ΔrG○ of lowering the temperature: a. NH3 (g) + HBr (g) → NH4Br (s) b. CaCO3 (s) → CaO (s) + CO2 (g) c. CH4 (g) + 3 Cl2 (g) → CHCl3 (g) + 3 HCl (g) (ΔfG○ for CHCl3 (g) is -70.4 kJ/mol)
Define an enzyme and explain the properties:specificity, affinity and saturation
Define an enzyme and explain the properties:specificity, affinity and saturation
1. A firm in perfect competition competes by lowering its price to sell more. Explain clearly...
1. A firm in perfect competition competes by lowering its price to sell more. Explain clearly why you agree or disagree with this statement.
Describe what is capillary barrier and explain mechanism behind capillary barrier for solid waste disposal ?
Describe what is capillary barrier and explain mechanism behind capillary barrier for solid waste disposal ?
What is the before and after effect of the current global pandemic and its effects on...
What is the before and after effect of the current global pandemic and its effects on global multinational ecosystem?
How can a company reverse a trend of higher current liabilities over current assets?
How can a company reverse a trend of higher current liabilities over current assets?
A sample of 40 transistors yielded a sample average saturation current of 9.46 milliamps, with a...
A sample of 40 transistors yielded a sample average saturation current of 9.46 milliamps, with a sample standard deviation of 0.58 milliamps. Give a 95% confidence interval for the true mean saturation current of this type of transistor. Show all work.
What, if any, effect would result from calculating saturation concentration when there was a lot excess...
What, if any, effect would result from calculating saturation concentration when there was a lot excess solid urea suspended in solution after saturation was reached? a. Saturation concentration would be falsely low b. There would be no effect c. Saturation concentration would be falsely high
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT