In this type of diode, we dope one side of a semiconductor piece with an acceptor impurity and another side with a donor impurity. Now, if we join the two types of semiconductors ptype and ntype together then a new device is formed called as pn junction diode. A perfect diode is a device that only allows current to flow through it in one direction, i. The reverse breakdown of a pn junction may occur either due to zener effect or avalanche effect. Since a junction forms between a p type and n type material it is called as pn junction. In vi characteristics of pn junction diode is two operating regions and three possible biasing conditions for the standard junction diode and these are. Simulation using multisim of pn junction diode characteristics. A semiconductor diode is prepared by joining p and n sections of a semi conducting. The lead connected to the ptype material is called the anode and the lead connected to the ntype material is the cathode. Reverse recovery characteristics when a diode is in forward conduction mode, a sudden reversal of the polarity of the applied voltage would not stop the diode current at once. Conduct the experiment for obtaining the forward bias vi characteristics of the given diode. Zener diode is heavily doped than the normal pn junction diode. It is acting as normal diode while forward biasing.
It is one of the simplest semiconductor devices as it allows current to flow in only one direction. To study the forward and reverse bias characteristics of diode and zener diode. V slightly different than jds, negative resistance. 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. A pn junction diode is a twoterminal electronics element, which can be classified as either. Octavian florescu 2 the pn junction diode schematic diagram ptype ntype id.
This causes electrons from nregion to get attracted to positive terminal of the battery and holes by the negative terminal. Pn junction diode characteristics electronic circuits and. This nonlinear characteristic illustrates that during the operation of the n junction, the resistance is not constant. The semiideal diode had a leakage current across the junction the reverse saturation current, shown by i. It has a particular voltage known as break down voltage, at which the diode break downs while reverse biased. The constant vz developed across the diode can then be applied to a load. Semiconductor, silicon, pn junction, forward bias, reverse bias, diode. Electronics tutorial about the pn junction diode and the vi characteristics of pn junction diode when used as a diode rectifier. In pn junction diode, n is at right and p is at left. It means that a zener diode can be used as an alternate current path. Do not repeat the wording in the lab manual procedures.
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. Voltampere vi characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. Thus the load voltage remains at constant by altering the current flow through the zener diode. Iv characteristic of a pn junction diode showing the forward turn on and the reverse. This was a bad thing before the whole avalanche breakdown, large current. Pn junction diode and characteristics of pn junction diode. Mar 23, 2018 simulation using multisim of pn junction diode characteristics. Therefore, like a vacuum diode, a semiconductor diode can also accomplish the. Electrostatic analysis of a pn diode pnjuntiondiode. The other differences between the pnjunction and zener diode are explained below in the comparison chart. We can then fill in the junction region of the band diagram as. May 20, 2016 this pn junction can be used to operate and implement the functions of a diode because it can conduct considerable current in the forward direction and roughly no current in the reverse direction. The credit of discovery of the pn junction goes to american physicist russel ohi of bell laboratories. Basic electronics notes on vi characteristics of zener.
Forward bias current flows reverse bias no current flow. The word diode can be explained as di means two and ode is obtained from electrode. Pn junction diode shows zero resistance in the forward direction and infinite resistance in the reverse direction. Working of a pn junction current iv characteristic of reverse bias a pn junction diode. An ammeter is connected in series and voltmeter in parallel, while the supply is controlled through a variable resistor. Pn junction diode junction diode symbol and static iv characteristics. By exploring the electrical properties of silicon, it is possible to acquire an understanding of the inner workings of the pn junction. But the diode continues to conduct in the opposite direction due to minority carriers that remain stored in pnjunction and the bulk semiconductor material. But the diode continues to conduct in the opposite direction due to minority carriers that remain stored in pn junction and the bulk semiconductor material.
Figure 7 iv curve of the silicon pn junction diode. In the case of normal diodes the diode damages at the break down voltage. Pn junction diode v i characteristics of pn junction diode. However, at ordinary room temperature, a potential difference of about 0. The diode conducts when forward bias is applied and it will introduce zero resistance in the circuit. 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. A key difference is that a pn diode contains two depletion regions of opposite type. Silicon a single silicon atom consists of fourteen negatively. Pdf v i characteristics of diode through computer researchgate. Zero bias no external voltage potential is applied to the pn junction diode. Zener diodes acts like normal pn junction diodes under forward biased condition. There is also a difference in the reverse bias region due to both material characteristics and fabrication of the diode junction. 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.
A pn junction is formed by joining ptype and ntype semiconductors together in very close contact. There are two operating regions and three possible biasing conditions for the standard junction diode and these are. The pn junction is the fundamental building block of the electronic age. To plot voltampere characteristics of silicon pn junction diode. This time consists of a transient and an interval of time before the diode attains a steady state. Vi characteristics of pn junction diode in 3biasing modes. Apr 05, 2019 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.
Image source forward biasing a pn junction diode is very simple. The pn junction biasing the pn junction the diode trouble shooting. Pnjunction diode and diode circuits 1 main properties of semiconductors 2 the pnjunction in equilibrium 3 the i v characteristics of the pnjunction 4 deviations from the ideal diode 5 analysis of the diode circuits 6 rectifier circuits. When carriers are injected across a forwardbiased junction, it emits incoherent light. Characteristics of junction diodes technical articles. 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. As shown in the figure, pn junction diode is a 2 terminal polarity sensitive device. Zener effect dominates at reverse voltages less than 5 volt whereas avalanche effect dominates above 5 v. A pn junction diode is formed by doping one side of a piece of silicon with a ptype dopant boran and the other side with a ntype dopant phosphorus. The vi characteristics or voltagecurrent characteristics of the pn junction diode is shown in the below figure. Please use the following format for your lab reports. Working of pn junction diode with biasing, characteristics.
Most of the commercial leds are realized using a highly doped n and a p junction. In this article, we will focus on the iv characteristics of the junction diode, specifically the pn junction. Diode is a twoterminal electronic component that conducts electric current in only one direction. Thus the vi characteristics of pn junction diode is verified. Before using this diode, it is necessary to know a little about its characteristics and properties with forward bias and reverse bias. Electrostatic analysis of a pn diode pn juntion diode. Jan 21, 2019 vi characteristics of pn junction diode. This paper shows the vi characteristics of diode through pc that records the. The vi characteristics of pn junction diode in forwarding bias are nonlinear, that is, not a straight line. When forward biased voltage is applied to the zener diode it allows large amount of electric current and blocks only a small amount of electric current. 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. The other differences between the pn junction and zener diode are explained below in the comparison chart. To obtain vi characteristics of pn junction diode electronics practical when p and n semiconductors are joined to make the pn junction semiconductor diode, the electrons near the pn junction jump from n to p and holes near the junction jump from p to n. This is the basic construction of the pn junction diode.
A practical circuit arrangement for a pn junction diode is as shown in the following figure. The diode is a device formed from a junction of ntype and ptype semiconductor material. The major difference between pn junction and the zener diode is that the pn junction diode allows current to pass only in the forward direction, whereas the zener diode allows the current to flow both in the forward and the reversed direction. A typical vi characteristic for a forward biased pn junction is shown in the figure below.
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. Iv characteristics pn junction diode reverse biasing a pn junction when the polarity of the battery is reversed, the cathode is connected to positive end of the battery and anode to negative. 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. 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 electrons and holes. Zener diodes when we first talked about practical diodes, it was mentioned that a parameter associated with the diode in the reverse bias region was the breakdown voltage, v br, also known as the peakinverse voltage piv. Pn junction diode is one of the fundamental elements in electronics. When the diode is forwardbiased, it can be used in led lighting applications. This pn junction can be used to operate and implement the functions of a diode because it can conduct considerable current in the forward direction and roughly no current in the reverse direction. 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.
Vi characteristics of pn junction diode electronics post. The term junction refers to the boundary interface where the two regions of the semiconductor meet. The pn junction diode is the basic semiconductor diode format. Definition ptype semiconductor is suitably joined to ntype semiconductor,to conduct surface is called pn junction. Pn junction diode baising and its vi characteristics. The pn junction is the fundamental building block of the. Pn junction diode, characteristics and applications 2020. In general, the cathode of a diode is marked by a solid line on the diode.
The barrier increase reduces the majority carrier diffusion to a negligible level. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light. A pn junction with open terminals excluding minority carriers f. Pn junction diode vi characteristics using multisim youtube. Jan 29, 2019 pn junction diode is one of the fundamental elements in electronics. So vi characteristics of a diode means plotting the graph for voltage across the diode versus the current through the diode.
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. It is also required to obtain the capacitancevoltage characteristics of the diode. The diode has two terminals called a cathode and an anode. Mar 26, 2017 in vi characteristics of pn junction diode is two operating regions and three possible biasing conditions for the standard junction diode and these are. Experimently find out whether the given diode is made of germanium or silicon. A semiconductor diode is prepared by joining p and n sections of a semi conducting material like germanium or silicon. It is seen that the forward current rises exponentially with the applied forward voltage. The analysis is very similar to that of a metalsemiconductor junction. There are three biasing conditions for pn junction diode and this is based on the voltage applied.
The slope of the pn junction diode in forwarding bias shows the resistance is very low. Normally the voltage is taken along the xaxis and current along yaxis. Semiconductor physics semiconductors and diodessemiconductors. P type and n type semiconductors, takenseparately are of very limited use. Zener diode is a pn junction diode specially designed to operate in the reverse biased mode. Zener diode is a reversebiased heavilydoped pn junction diode which operates in the breakdown region. Basic electronics notes on vi characteristics of zener 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 light emitting diode led is essentially a pn junction diode. The vi characteristics of a zener diode can be divided into two parts i forward characteristics.
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