If the diode is forward biased, it allows the electric current flow. When carriers are injected across a forwardbiased junction, it emits incoherent light. Najmabadi, ece65, winter 2012 high concentration of h on the p side holes diffuse towards the junction high concentration of e on the n side electrons diffuse towards the junction n side is positively charged because it has lost electrons. Ppt pn junction powerpoint presentation free to download. From the above, it follows that zero power dissipation occurs in an ideal diode. When ptype semiconductor is suitably joined to ntpye semiconductor,thesuitably joined to ntpye semiconductor,the contact surface is calleed pn junction. The behaviour of the pn junction with regards to the potential barriers width produces an asymmetrical conducting two terminal device, better known as the pn junction diode. Although it is not discussed majorly outside the concept of pn junction diode and sometimes the transistor, a pn junction is an essential topic in semiconductor electronics.
The pn junction biasing the pn junction the diode trouble shooting. A pn junction diode is one of the simplest semiconductor devices around, and which has the characteristic of passing current in only one direction only. A k schematic symbol for a pn junction diode p n representative structure for a pn junction diode zener diodes. Ppt diodes powerpoint presentation free to download id.
This video explains complete process of diode working i. Pn junction is a significant building block and it is one among the indispensable structures. After the pn junction diode was developed in the year 1940s, the diode was first exercised as a highpower rectifier, lowfrequency during the year 1952. Jan 04, 2020 a pn junction is the simplest form of the semiconductor diode. Oct 09, 2018 a pn junction diode is a two terminal single crystal semiconductor device whose one side is doped with acceptors and other side by donors.
Semiconductor, silicon, pn junction, forward bias, reverse bias, diode. The energy gap between the valence level and the conduction level is midway between that of insulators and conductors such as metals, and thermal energy causes. Difference between schottky diode and pn junction diode. If we join a piece of p type material to a pieceof n type material such that the crystalstructure remains continuous at the boundary, a pn junction is formed 2. Pn junction can basically work in two modes, a battery is connected to the diode oforward bias mode positive terminal connected to pregion and negative terminal connected to n region areverse bias mode negative terminal connected to pregion and positive terminal connected to n region. Note that a pn junction diode cannot be made by simply pushing a piece of ptype against another of ntype. Lecture 15 the pn junction diode i iv characteristics november 1, 2005 contents. Semiconductor pn junction diodes physically, diodes are formed by the interface between two regions of oppositely doped semiconductor i. What is pn junctionwhat is pn junction pnjunctionpnjunction. Are specifically designed to operate under reverse breakdown conditions. Definition, symbol, and types of diodes electrical4u. Due to this large power gets dissipated in the diode which may damage it permanently. However if the diodes terminals are shorted together, a few holes majority carriers in the ptype material with enough energy to overcome the potential barrier will move across the junction against this barrier potential. Diode animation free download as powerpoint presentation.
Apr 05, 2019 in this tutorial, we will learn about pn junction diodes and in particular the characteristics and working of pn junction diode. By exploring the electrical properties of silicon, it is possible to acquire an understanding of the inner workings of the pn junction. Animation how a p n junction semiconductor works forward. Note to those familiar with a diode turn on voltage. The forward bias voltage required for a silicon diode v t 0. Diode animation pn junction semiconductors free 30day. How diode works, animation diode, animation pn junction, working of pn junction, how does a pn junction semiconductor works, what is avalanche breakdown, what is drift. A pn junction is the metallurgical boundary between the n and pregions of a semiconductor crystal. Pn junction diode baising and its vi characteristics. Semiconductor physics semiconductors and diodessemiconductors. It is used for many forms of rectification for current levels both large and small, as well as high and low voltage levels, and it finds many uses in all manner of electronic circuits. An attractive animation is presented in this video with complete voice description.
Reverse bias external battery makes the cathode more positive than the anode a tiny current flows opposite to the arrow in the symbol. When ptype semiconductor is suitably joined to ntpye semiconductor,thesuitably joined to ntpye semiconductor,the contact surface is calleed ntact surface is calleed. A diode is also a tool that exclusively permits unidirectional flow of current if the diode is operated at a particular voltage level. We have also learned about diffusion current, depletion region. Electronics animation archives instrumentation tools. The pin diode is an alteration of the pn junction for particular applications. A specific arrangement of diodes can convert ac to pulsating dc, hence it is sometimes also called as a rectifier. This energy comes from the external voltage applied across the diode. They are also called pn diodes in analogy with vacuum diodes.
The pn junction diode is the typical diode that has been used in the previous circuits. Microsoft powerpoint inc221 lecture2 diode pn junction. Pn junction tutorial introduction to pn junction diodes. The pn junction is a versatile element, which can be used as a. In this tutorial, we will learn about pn junction diodes and in particular the characteristics and working of pn junction diode. Semiconductor simulations, animations and java applets background. Ppt pn junction diode powerpoint presentation free to. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light. Doping with acceptor creates p type semiconductor while doping with donors produces n type. However if the diodes terminals are shorted together, a few holes majority carriers in the ptype material with enough energy to overcome the potential barrier will move. Silicon a single silicon atom consists of fourteen negatively. Forward bias current flows reverse bias no current flow. Schottky diode pn junction diode animation free download 3741. A pn junction diode is a two terminal single crystal semiconductor device whose one side is doped with acceptors and other side by donors.
Formation of depletion layer the excess electrons in the n region cross the junction and combine with the excess holes in the p region. Pn junction diode characteristics forward bias external battery makes the anode more positive than the cathode current flows in the direction of the arrow in the symbol. Powerpoint slide on pn junction diode compiled by paridhi gupta. To understand how a pnjunction diode works, begin by imagining two separate bits of semiconductor, one ntype, the other ptype. The name diode is derived from diode which means a device that has two electrodes. So, in this pn junction tutorial, we will discuss some of the basics of a pn junction, how a pn junction is formed, characteristics of pn junction and many other aspects. On formation of pn junction electrons from nlayer and holes from. Pn juction animation 20200501 0 comments introduction to semiconductors. For each approved ppt you will get 25 credit points and 25 activity score which will increase your profile visibility. The most frequently used sentence in this course will be. The pn junction diode is the basic semiconductor diode format. However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as the diode has an exponential currentvoltage iv relationship. A diode is nothing more than a pn junctiona diode is nothing more than a pn junction. Their values depend on the individual doping concentrations forward biasing the junction shrinks the depletion width and the barrier, allowing thermionic emission and higher current.
What is pn junctionwhat is pn junction pn junctionpn junction. The occurrence of an intrinsic layer can significantly increase the breakdown voltage for the application of high. A pn junction with open terminals excluding minority carriers f. The point at which the diode changes from no bias condition to forward bias condition happens when the electron and holes are given sufficient energy to cross the pn junction. Simplified physical structure construction on a cmos chip. At the junction, majority carriers diffuse across the junction, and this creates a depletion layer and a barrier potential v barrier across the junction. The voltage v barrier causes an opposing current flow, and the two flows form an equilibrium. The types of diode are as follow1 zener diode 2 pn junction diode 3 tunnel diode 4 varractor diode 5 schottky diode 6 photo diode 7 pin diode 8 laser diode 9 avalanche diode 10 light emitting diode.
The pn junction is the fundamental building block of the electronic age. Such junctions show a pronounced rectifying behavior. This understanding will lay a better foundation for exploring further into different aspects of semiconductor electronics. Diodes exclusively block current in the reverse direction whereas the reverse voltage is within a restricted vary and if not reverse barrier breaks and conjointly the voltage at that this breakdown happens is termed. A pn junction is the simplest form of the semiconductor diode. Pn junctions consist of two semiconductor regions of opposite type. In ideal conditions, this pn junction behaves as a short circuit when it is forward biased, and as an open circuit when it is in the reverse biased. When a diode is connected in a zero bias condition, no external potential energy is applied to the pn junction.
This is the voltage required to reach a flat band diagram and sets an upper limit typically an overestimate for the voltage that can be applied to a diode before it burns itself up. Ppt pn junction diode powerpoint presentation, free. A free powerpoint ppt presentation displayed as a flash slide show on. Bring them together and join them to make one piece of semiconductor which is doped differently either side of the junction. It is derived from diode which means a device having two electrodes. The pn junction has the very useful property that electrons are only able to flow in one direction. Pin diode working characteristics and its applications. Lots of electrons on the left hand side of the junction want to diffuse to the right and lots of holes on the right hand side of the junction want to move to the left.
When a ptype semiconductor is suitably joined to ntype semiconductor, the contact surface in called pn junction. Pnjunction diode characteristics forward bias external battery makes the anode more positive than the cathode current flows in the direction of the arrow in the symbol. Semiconductor diode consists of a pn junction with two contacts attached to the p and n sides. Diode working principle and types of diode electrical. This presentation is a very informative piece on pn junction diode an important part of electronics education.
A light emitting diode led is essentially a pn junction diode. An additional electrons from the n region are repelled by the net negative charge of the p region. Najmabadi, ece65, winter 2012 high concentration of h on the p side holes diffuse towards the junction high concentration of. What is pn junctionwhat is pn junction pnjunctionpn junction. A diode is a simple electrical device that allows the flow of current only in one direction. Full animated download to view unbiased diode, forward biased, reverse bi. Pn junctions ece 663 in summary a pn junction at equilibrium sees a depletion width and a builtin potential barrier. Pn junction diode engi 242 elec 222 pn junction diode diode model analysis ideal approximation exact diode specification sheets diode resistance static resistance rd. P type and n type semiconductors, takenseparately are of very limited use. To understand how a pn junction diode works, begin by imagining two separate bits of semiconductor, one ntype, the other ptype. Lecture 15 the pn junction diode i mit opencourseware. Most of the commercial leds are realized using a highly doped n and a p junction.
1288 459 1130 785 1622 1543 1403 668 1490 418 980 234 1135 1292 1400 929 388 1201 499 1235 1294 157 74 559 148 406 1427 978 843 1020 1268 538 1289 265