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

Wcdma, what is that mean and explain

what is that mean and explain

Common-emitter configuration, Common-emitter configuration: The commo...

Common-emitter configuration: The common-emitter that is abbreviated as CE transistor configuration is displayed in figure.  The transistor terminal common to both the input

What is interrupt service routine, What is interrupt service routine? I...

What is interrupt service routine? Interrupt means to break the sequence of operation. Whereas the CPU is executing a program an interrupt breaks the normal sequence of impleme

N-type semiconductor, a)  Sketch the variation of electron concentration wi...

a)  Sketch the variation of electron concentration with temperature for i)  an n-type semiconductor doped with 1021  donors m-3 ii)  an intrinsic semiconductor.  b)  Expla

Electrical fault which might occur in a circuit, Question 1: (a) Descri...

Question 1: (a) Describe the three main types of electrical fault which might occur in a circuit. (b) What is three phase electric power? Give its advantages. (c) Explain th

Energy band diagram, Sketch the Fermi-Dirac distribution function, F(E), al...

Sketch the Fermi-Dirac distribution function, F(E), alongside the energy band diagram for an n-type semiconductor, indicating the position of the Fermi level, EF, and the donor lev

Logic Gates, XOR gate BY using NAND gate Only

XOR gate BY using NAND gate Only

Excitation, excitation in an ac generator

excitation in an ac generator

Explain the limiting the spectrum, Explain the Limiting the Spectrum Th...

Explain the Limiting the Spectrum This low-pass filter is known an anti-aliasing filter. These filters are originated at the input to most applications. Since they are required

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