Pn-junction under bias, Electrical Engineering

Assignment Help:

Q. pn-Junction under Bias?

Let an external source be connected between the p- and n-regions, as shown in Figure (a). (b) shows the circuit representation of the pn-junction or diode, and its external circuit. The voltage source V, called the bias, either decreases or increases the potential barrier, thereby controlling the flow of carriers across the junction. With V = 0, the barrier is unaffected and the pn-junction has zero current. Positive values of V, known as forward biasing, decrease the potential barrier, thereby increasing the number of electrons and holes diffusing across the junction. The increased diffusion results in a net current, called the forward current, from the p-tothe n-region. With increased V, the forward current further increases rapidly because the barrier is reduced even further.Making V negative (reverse biasing), on the other hand, increases the potential barrier and reduces the number of carriers diffusing across the boundary. The drift component produced by the electric field from the n-tothe p-region causes a small current, called the reverse current (or saturation current) IS. The magnitude of the saturation current depends on the doping levels in the p- and n-type materials and on the physical size of the junction. Increasing the reverse bias, however, does not affect the reverse current significantly until breakdown occurs.

1316_pn-Junction under Bias.png


Related Discussions:- Pn-junction under bias

Physical operation of the junction of diode, Q. Physical operation of the j...

Q. Physical operation of the junction of diode? The physical operation of the junction can be described in terms of the charge-flow processes. Usually there is a greater concen

Pn diode, PN Diode The current-voltage characteristics are of major ...

PN Diode The current-voltage characteristics are of major concern in the learning of semiconductor devices with light entering like a third variable in optoelectronics devic

Tariff policy - electricity policies, National tariff policy: The Centr...

National tariff policy: The Central Government notified the National Tariff Policy on January 6, 2006, for the power sector in line along with the Section 3 of the EA, 2003. Wi

What do you mean by frequency response, Q. What do you mean by Frequency Re...

Q. What do you mean by Frequency Response? As with all electronic circuits, op amps have limited frequency response. Because of the negative feedback of the circuit, the passba

Determine the analog output voltage, Q. Analyze the 2-bit R-2R ladder-netwo...

Q. Analyze the 2-bit R-2R ladder-network D/A converter, and corresponding to binary 01, 10, and 11, obtain the equivalent circuits and determine the analog output voltage as a frac

Explain the term superscalar architecture, Question 1: a) Describe how...

Question 1: a) Describe how pipelining can improves the efficiency of the fetch-execute cycle. b) Explain the term superscalar architecture. c) Explain the term prin

Explain the purpose of the i/o instructions in and out, Explain the purpose...

Explain the purpose of the I/O instructions IN and OUT. The IN instruction is used to move data from an I/O port into the accumulator. The OUT instruction is used to move d

Resistance temperature sensor, A Platinum resistance temperature sensor has...

A Platinum resistance temperature sensor has a resistance of 120 ohm at 0°C and forms one arm of a Wheatstone bridge. At this temperature the bridge is balanced with each of the ot

Calculate the amplitude and the frequency of the sine wave, (a) The key el...

(a) The key elements of a protocol are the syntax, semantics and timing. Give a brief explanation of each of these key elements. (b) A file contains 4 million bytes. Compare

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd