Pn junction diode v i characteristics of pn junction diode. The forward biasing and reverse biasing of the zener. The vi characteristics or voltagecurrent characteristics of the pn junction diode is shown in the below figure. A pn junction is formed by joining ptype and ntype semiconductors together in very close contact. Forward bias operation the pn junction supports unidirectional current flow. The vi characteristics of a zener diode is shown in the below figure. The slope of the pn junction diode in forwarding bias shows the resistance is very low. And based on the applied voltage, there are three possible biasing conditions for the pn junction diode, which are as follows. Now, if we join the two types of semiconductors ptype and ntype together then a new device is formed called as pn junction diode. Its characteristics are completely different from the pn junction diode.
Ideal diode and real diode a diode is said to be an ideal diode when it is forward biased and acts like a perfect conductor, with zero voltage across it. This video lecture explains the vi characteristics of the zener diode. Basic electronics notes on vi characteristics of zener diode. Voltampere characteristics of pn diode are studied. Pn junction diode is one of the fundamental elements in electronics. The vi characteristics of pn junction diode in forwarding bias are nonlinear, that is, not a straight line. It may be noted that the forward characteristics shifts upwards with increase in temperature. On the other hand, the reverse characteristics shifts downwards with the increase in. Working of pn junction diode with biasing, characteristics. Pn junction diode plays a vital role in our electronic fields, because of their unique property current flows in only one direction they are used in many electronic or electrical circuits like rectifiers, switches, clippers, clampers, voltage multipliers in this article, we will learn about what is a pn junction diode and how it works and also effect on pn junction diode with different. Pn junction diode characteristics electronic circuits and.
Simulator procedure as performed through the online labs select the characteristics of diode from the. Basic electronics notes on vi characteristics of zener. The analysis is very similar to that of a metalsemiconductor junction. The pn junction is the fundamental building block of the electronic age. The short circuit current is a function of the pn junction area collecting the light. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light. Electrostatic analysis of a pn diode pn juntion diode. Thus the load voltage remains at constant by altering the current flow through the zener diode.
The current in this biasing is low till breakdown is reached and hence the diode looks like an open circuit. Iv characteristics uwhenever an electron on the pside moves to the nside, it is replaced by an electron generated through one of the rg centers ohmic ohmic minority minority excess majority carriers alocal excess majority carriers alocal e e excess carriers move to the contact with a relaxation time. Apr 23, 2018 semiconductor pn junction diode is the simplest semiconductor device. Pn junction diode free download as powerpoint presentation. Aug 14, 2019 the above are some of the basics of the pn junction diode and this article covers about the vi characteristics of the pn junction diode. When forward biased voltage is applied to the zener diode, it works like a normal diode.
The diode is a device formed from a junction of ntype and ptype semiconductor material. 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. Sep 08, 2018 this video lecture explains the vi characteristics of the zener diode. The vi characteristics of the ideal diode are shown in the figure below. The tunnel diode was first introduced by leo esaki in 1958. Zener diode is a reversebiased heavilydoped pn junction diode which operates in the breakdown region. The vi characteristics of a zener diode can be divided into two parts i forward characteristics.
Rajiv gandhi college of engineering and technology itt32 electronic devices and circuit uniti diode current equation vi characteristics of pn junction diodeapplication half wave rectifier and full wave rectifiers with and without filters derivation of ripple factor rectification of efficiency and tufzener diode and. Working of pn junction diode if an external potential is applied to the terminals of pn junction, it will alter the potential between the p and nregions. The pn junction region of a junction diode has the following important characteristics. The junction of n and p semiconductors is free of charge carriers. It is also required to obtain the capacitancevoltage characteristics of the diode. Zener effect dominates at reverse voltages less than 5 volt whereas avalanche effect dominates above 5 v. A pn junction diode is a twoterminal electronics element, which can be classified as either. This nonlinear characteristic illustrates that during the operation of the n junction, the resistance is not constant.
By exploring the electrical properties of silicon, it is possible to acquire an understanding of the inner workings of the pn junction. Zener diode definition, vi characteristics, and breakdown. The vi characteristic of pn junction diode indicates that the forward current is negligible up to the knee voltage. Vi characteristics of pn junction diode in 3biasing modes. Zero bias no external voltage is applied to the pn junction diode. Explain the effect of temperature on pn junction diode. The constant vz developed across the diode can then be applied to a load. A pn junction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous tutorial is achieved without any external voltage being applied to the actual pn junction resulting in the junction being in a state of equilibrium. Apr 05, 2019 pn junction diode is a two terminal device, the characteristics of diode depends on the polarity of the external potential applied to the pn junction diode. Depletion layer opposes only the the majority carrier not minority carrier. Depletion layer opposes only the the majority carrier not minority carr. Vi characteristics of pn junction diode topics covered. Similarly, when the diode is reversed biased, it acts as a perfect insulator with zero current through it. Pn junction diode and characteristics of pn junction diode.
The vi characteristic of zener diode indicates that characteristic of zener diode in forward bias is same as pn junction diode. Forward vi characteristics of pn junction diode if the positive terminal of the battery is connected to the ptype semiconductor and the negative terminal of the battery is connected to the ntype semiconductor, the diode is said to be in forward bias. Vi characteristics of pn junction diode electronics post. A pnjunction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous tutorial is achieved without any external voltage being applied to the actual pn junction resulting in the junction being in a state of equilibrium. The word diode can be explained as di means two and ode is obtained from electrode. P type and n type semiconductors, takenseparately are of very limited use. The term junction refers to the boundary interface where the two regions of the semiconductor meet. Normally the voltage is taken along the xaxis and current along yaxis. Dec 16, 2017 a tunnel diode is a special type of pn junction diode that shows the negative resistance between two values of forward voltage ie, between peak point voltage and valley point voltage. The horizontal line in the below figure represents the amount of voltage applied across the pn junction diode whereas the vertical line represents the amount of current flows in the pn junction diode. Image source forward biasing a pn junction diode is very simple. Note to those familiar with a diode turn on voltage.
Electrostatic analysis of a pn diode pnjuntiondiode. The contact surface between the layers of ptype and ntype semiconductor pieces plated together so as to form a pn junction is called the pn junction. Before using this diode, it is necessary to know a little about its characteristics and properties with forward bias and reverse bias. Thus if we kept the voltage constant, as we increase temperature the current increases.
Tunnel diode basics, operation, vi characteristics. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse bias components equipments required. Pn junction diode is a device made of two semiconductor material joined together with the required amount of impurity. Here you will learn, how the zener diode is used in reverse biasing. Semiconductors contain two types of mobile charge carriers, holes and electrons. Plot a graph with reverse voltage along x axis and reverse current along y axis. Vi characteristics of pn junction diode in reverse bias in this type of bias, the characteristic curve of the diode is shown in the fourth quadrant of the below figure. Voltampere characteristics of diode in forward bias condition. The symbol of zener diode is similar to the normal pn junction diode, but with bend edges on the vertical bar. Semiconductor pn junction diode working pn diode vi. In general, the cathode of a diode is marked by a solid line on the diode. Jan 29, 2019 pn junction diode is one of the fundamental elements in electronics. Vi characteristics of zener diode vi characteristics of. Reverse saturation current in a silicon pn junction diode nearly doubles for very a.
Diode is a twoterminal electronic component that conducts electric current in only one direction. Pn junction diode shows zero resistance in the forward direction and infinite resistance in the reverse direction. What is the effect of temperature in the diode reverse characteristics. The holes are positively charged while the electrons negatively charged. The reverse breakdown of a pn junction may occur either due to zener effect or avalanche effect. As you have learned, forward bias produces the current through a pn junction diode and reverse bias essentially prevents current, except for a negligible reverse current. In reverse bias, a negligible constant current flow through the zener diode but the current becomes abruptly large at certain voltage.
Read more pn junction diode and its working principle. Pn junction diode junction diode symbol and static iv characteristics. Depletion region created across the pn junction by the initial movement of majority carrier across the junction. Voltampere vi characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. There are two operating regions and three possible biasing conditions for the standard junction diode and these are. Pn junction diode characteristics explained in detail.
Silicon a single silicon atom consists of fourteen negatively. A key difference is that a pn diode contains two depletion regions of opposite type. Pn junction diode vi characteristics in forward and reverse bias. Conduct the experiment for obtaining the forward bias vi characteristics of the given diode. This potential difference can alter the flow of majority carriers, so that the pn junction can be used as an opportunity for the diffusion of. A diode is said to be an ideal diode when it is forward biased and acts like a perfect conductor, with zero voltage across it. When the diode is forwardbiased, it can be used in led lighting applications. The graph shows the reverse vi characteristics of the given pn junction diode. Experimently find out whether the given diode is made of germanium or silicon. Vi characteristics are used for explaining the relationship between voltage and current characteristics of any given electrical component.
Pn junction diode vi characteristics in forward and. It means that a zener diode can be used as an alternate current path. A order flows through the diode and it increases gradually to maximum at large reverse voltage. Vi characteristics of zener diode vi characteristics of pn. The potential developed across the junction due to the influence of the carriers is termed as diffusion voltage. Pn junction diode baising and its vi characteristics. Pn junction diode, characteristics and applications 2020. Since a junction forms between a p type and n type material it is called as pn junction. Connecting a pn junction to an external voltage source is biasing a pn junction. A pn junction diode is a twoterminal electronics element, which can be classified as either step graded or linear graded. One terminal of pn junction diode is anode and other is cathode.
Pn junction diode, its characteristics and applications. Jan 21, 2019 vi characteristics of pn junction diode. With proper biasing, pn diode allows current to flow in single direction. Simulator procedure as performed through the online labs select the characteristics of diode from the drop down list. 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. 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. Zero bias no external voltage potential is applied to the pn junction diode. Similarly, the open circuit voltage, v oc, is the potential that develops across the terminals of the solar cell when the external load resistance is very large, r load for silicon based cells a. These materials are ntype, having electrons are majority carrier and ptype material, having holes are majority carrier. What are the characteristics of a pn junction diode.
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