P and n type materials are joined together to form a pnp and n type materials are joined together to form a pn junction a diode is nothing more than a pn junctiona diode is nothing more than a pn junction. Electronics projects pn junction diode working animation pn junction diode is formed by joining semiconductor materials, such as silicon. This allows electrical current to pass through the junction only in. When a ptype semiconductor is suitably joined to ntype semiconductor, the contact surface in called pn junction. 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. The pn junction diode is the basic semiconductor diode format. As shown in the figure, pn junction diode is a 2 terminal polarity sensitive device. A semiconductor diodes currentvoltage characteristic can be tailored by selecting the semiconductor materials and. The pn junction has the very useful property that electrons are only able to flow in one direction.
This creates barrier that reqqpp yuires approximately. Pn junction is also a fundamental building block of many other semiconductor electronic devices such as transistors, solar cells, light emitting diodes, and integrated circuits. Diode current voltage iv characteristics semiconductor diode consists of a pn junction with two contacts attached to the p and n sides v p n 0 qv i i s exp 1 kt i s is usually a very small current, i s. Pn junctions consist of two semiconductor regions of opposite type. Write down all circuit equations and simplify as much as possible 2. Semiconductor pnjunction diodes physically, diodes are formed by the interface between two regions of oppositely doped semiconductor i. Pn diodes forward bias, small signal model, bjts prof j.
Pn junctions ece 663 in summary a pn junction at equilibrium sees a depletion width and a builtin potential barrier. Dec 26, 2016 an attractive animation is presented in this video with complete voice description. To understand how a pnjunction diode works, begin by imagining two separate bits of semiconductor, one ntype, the other ptype. Pn junction diode baising and its vi characteristics. Forward bias current flows reverse bias no current flow. Ppt pn junction diode powerpoint presentation, free. Since current is only due to drifting of electrons, there is a limit to the increase in current as well. This pn diode applications are very useful for beginners. Great powerpoint template for presentations on electronics, semiconductor materials, radio demodulation, overvoltage protection, etc. A pnjunction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction. Also, it explains the phenomenon of shockleyqueisser limit.
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. Its main electrical property is that it rectifies allow current to flow easily in one direction only. There are several types of junction diodes, which either emphasize a different physical aspect of a diode often by geometric scaling, doping level, choosing the right electrodes, are just an application of a diode in a special circuit, or are really different devices like the gunn and laser diode and the mosfet. Voltagecurrent relationship for a pn junction diode 39 currentvoltage characteristics the ideal diode positive voltage yields finite current negative voltage yields zero current real diode 40 the ideal diode equation 41 semiconductor diode opened region. Bring them together and join them to make one piece of semiconductor which is doped differently either side of the junction.
Microsoft powerpoint inc221 lecture2 diode pn junction. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. At the junction, majority carriers diffuse across the junction, and this creates a depletion layer and a barrier potential v barrier across the junction. Pn junction formation and how it works circuitstoday. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light. Dynamic ppt templates download the chinese new year spring festival peony ppt template backgrounds beijing ppt template dove ppt template. Doped semiconductors ntype materials ptype materials diodes and transistors. Diode current voltage iv characteristics semiconductor diode consists of a pn junction with two contacts attached to the p and n sides v p n 0 qv i i s exp 1 kt i s is usually a very small current, i. Ppt diodes powerpoint presentation free to download id.
Image source forward biasing a pn junction diode is very simple. 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. 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. Otherwise, we would be able to draw energy from an isolated pn junction, which violates conservation of energy. 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.
There are three biasing conditions for pn junction diode and this is based on the. In the nonconduction region, ideally all of the voltage is across the diode, the current is 0a, the reverse resistance r r is defined as r r v r i r, the diode acts like open. In 1906, lee dee forest added a 3rd electrode called a control grid and the triode, which is used as amplifier, switch the application of triode created a new era in broadcasting with the invention of the crystal radio sensor by pickard, 1912. Simply explains how a pn junction is formed from ptype and ntype. Use the diode equation for that state to solve the circuit equations and find i d and v d 3. Ppt pn junction powerpoint presentation, free download id. 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. There are two operating regions and three possible biasing conditions for the standard junction diode and these are. View and download powerpoint presentations on diodes and transistor ppt. Pn junction diode applications pn diode applications. Smith context this lecture will discuss zdiode currents in forward and reverse bias 6.
Note to those familiar with a diode turn on voltage. The p positive side contains an excess of holes, while the n negative side contains an excess of electrons in the outer shells of the electrically neutral atoms there. A diode is nothing more than a pn junctiona diode is nothing more than a pn junction. Simplified physical structure construction on a cmos chip. Such junctions show a pronounced rectifying behavior. An attractive animation is presented in this video with complete voice description. Najmabadi, ece65, winter 2012 high concentration of h on the p side holes diffuse towards the junction high concentration of. Here you may find a good video with animation, which explains the formation of pn junction.
We will understand the process of doping with the help of this example. A diode is a twoterminal electronic component that conducts current primarily in one direction. A pn junction is the metallurgical boundary between the n and pregions of a semiconductor crystal. 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. From the above, it follows that zero power dissipation occurs in an ideal diode. View and download powerpoint presentations on zener diode ppt.
This energy comes from the external voltage applied across the diode. The forward bias voltage required for a silicon diode v t 0. It is composed of a horizontal line attached to a triangle with its tip attached to a vertical line and then another horizontal line. The voltage v barrier causes an opposing current flow, and the two flows form an equilibrium. The credit of discovery of the pn junction goes to american physicist russel ohi of bell laboratories. Ppt semiconductor ppt powerpoint presentation free to. The pn junction biasing the pn junction the diode trouble shooting. A pn junction is a boundary or interface between two types of semiconductor materials, ptype and ntype, inside a single crystal of semiconductor.
Full animateddownload to view unbiased diode, forward. Zero bias no external voltage potential is applied to the pn junction diode. 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. The credit of discovery of the pn junction goes to american physicist russel ohi of bell. For example, diodes are used to regulate voltage zener diodes, to protect circuits from high voltage surges. This presentation is a very informative piece on pn junction diode an important part of electronics education. A pn junction diode is made by forming a ptype region of material directly next to a ntype region. The pn junction can be formed by pushing a piece of ptype silicon into close contact with a piecce of ntype silicon.
Semiconductor, silicon, pn junction, forward bias, reverse bias, diode. A pn junction with open terminals excluding minority carriers f. Chinese new year animated ppt template for free download. When a diode is connected in a zero bias condition, no external potential energy is applied to the pn junction. This is bc the metalsemiconductor junction at the terminals counteract and balance v 0. Zener breakdown does not result in damage of diode. These powerpoint shapes are shown in white, against a blue background. Recipe for solving diode circuits state of diode is unknown before solving the circuit 1. Pn junction diode and diode characteristics electronicstutorials. Pn junction diode junction diode symbol and static iv characteristics. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Smith department of eecs university of california, berkeley eecs 105 spring 2004, lecture 20 prof.
Reverse bias external battery makes the cathode more positive than the anode a tiny current flows opposite to the arrow in the symbol. 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. Ppt semiconductor diodes powerpoint presentation free to. This diode power supply powerpoint template illustrates the symbol for a diode. You just need to take a battery whose values can be varied from o to v volts, connect its positive terminal to the pside of pn junction diode and then connect the negative terminal of battery to the nside of the pn junction diode. This lecture uncovers the basic science of semiconductor devices and solar cells, including pn junction and photovoltaic effects. Semiconductor physics semiconductors and diodessemiconductors. Semiconductor pn junction diodes physically, diodes are formed by the interface between two regions of oppositely doped semiconductor i.
The pn junction is the basic element of all bipolar devices. Ppt diodes powerpoint presentation free to download. P type and n type semiconductors, takenseparately are of very limited use. Find powerpoint presentations and slides using the power of, find free presentations research about diodes and transistor ppt. Semiconductors, diodes, transistors horst wahl, quarknet presentation, june 2001 electrical conductivity.
Electronics projects pn junction diode working animation. The most frequently used sentence in this course will be. Find powerpoint presentations and slides using the power of, find free presentations research about zener diode ppt. Was constructed with 2 electrodes in the form of a vacuum tube. This page of application notes section covers pn junction diode applications. This pn junction forms a most popular semiconductor device known as diode. This video explains complete process of diode working i. 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. Dec 27, 2015 electronics projects pn junction diode working animation pn junction diode is formed by joining semiconductor materials, such as silicon. 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.
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