A solar cell is a semiconductor pn junction diode as shown in figure 1. A perfect diode is a device that only allows current to flow through it in one direction, i. In the reverse bias condition the zener diode is an open circuit and only a small leakage current is flowing as shown on the exaggerated plot. The first quadrant of the vi characteristics curves shows the forward operation of the diode. This paper examines various electrical characteristics of a typical silicon junction diode. The currentvoltage characteristics of four devices. 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. Solar cells are usually coated with antireflective materials so that they absorb the maximum amount of light energy. This article gives an overview of pn junction diode, pn junction diode in zero bias, forward and reverse bias and vi characteristics of pn. Jan 18 gate coaching, gate syllabus 37090 views 25 comments on vi characteristics of zener diode zener diode is a reversebiased heavilydoped pn junction diode which operates in the breakdown region. Plot the vi characteristics and calculate the resistance levels. Diode circuits operating in the reverse breakdown region. A varactor diode is a pn junction diode that is especially operated in reverse biased mode.
A pn junction diode is a twoterminal electronics element, which can be classified as either step graded or linear graded. Electronics tutorial about the pn junction diode and the vi characteristics of pn junction diode when used as a diode rectifier. Basic electronics notes on vi characteristics of zener diode. To draw the voltagecurrent vi characteristics of zener diode. The same number of minority carriers are being swept. This property of diode makes it an essential component of. Vi characteristics of zener diode vi characteristics of. This is the basic construction of the pn junction diode. Here you will learn, how the zener diode is used in reverse biasing. The basic circuit symbol of the diode is shown on figure 1. Voltampere characteristics of pn diode are studied.
Pn junction diode, its characteristics and applications. In reverse bias, a negligible constant current flow through the zener diode but the current becomes abruptly large at certain voltage. 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 and therefore we can not described its operation by simply using an equation such as ohms law. Vi characteristics are used for explaining the relationship between voltage and current characteristics of any given electrical component. Pn junction diode, characteristics and applications 2020.
Although it is possible to collect the data for this lab very quickly, it is essential that you understand the different regions found in the iv characteristics of these diodes and the mechanisms by which current flows through them. Vi characteristics of pn junction diode electronics post. 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. The polarity shown, attracts electrons to the left and holes to the right. Shockley diode circuit with working and characteristics. To draw the iv characteristic curve of a pn junction in forward bias and reverse bias. The vi characteristics of pn junction diode in forwarding bias are nonlinear, that is, not a straight line. Pn junction diode, voltmeter 02volt, voltmeter 030 volt, miliammeter, microammeter, variable source 02 volt and 030 volt.
Static characteristics of junction diode, point contact. Leds are pn junction diodes that emit light at various frequencies. Ece class notes having important engineering viva questions and answers pdf free download for ece students. Zero bias no external voltage potential is applied to the pn junction diode. Study of different types of diode characteristics and its applications objective to draw the voltagecurrent vi characteristics of pn junction diode. Vi characteristics of zener diode the vi characteristics of a zener diode. The junction is said to be forward biased when the psection of the diode is connected to the positive terminal of the battery and the nsection of the diode is connected to the negative terminal of the battery. In general, the cathode of a diode is marked by a solid line on the 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. Jan 29, 2019 pn junction diode is one of the fundamental elements in electronics. This is the voltage across the diode at which it starts conducting. Normally the voltage is taken along the xaxis and current along yaxis. What are the characteristics of a pn junction diode.
The large surface area indicated in light blue is exposed to incident light energy. Jan 26, 2016 draw the vi characteristics of an ideal diode. 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. Draw the reverse characteristics of zener diode and determine its break down voltage. This understanding will lay a better foundation for exploring further into different aspects of semiconductor electronics.
Calculate the resistance in forward bias and reverse bias. The light emitting diode or led as it is more commonly called, is basically just a specialised type of diode as they have very similar electrical characteristics to a pn junction diode. 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. Dec 02, 2016 to draw the characteristic curve of a zener diode and to determine its reverse breakdown voltage. Both silicon and germanium can be combined with other elements called dopants to create solidstate electronic devices, such as diodes, transistors and photoelectric cells. Dec 02, 2016 to draw the iv characteristic curve of a pn junction in forward bias and reverse bias physics lab manualncert solutions class 12 physics sample papers aim to draw the iv characteristic curve of a pn junction in forward bias and reverse bias. To draw the volt ampere characteristics of junction diode, point contact diode and zener diode and determine their knee voltage, and forward resistance. To draw the iv characteristic curve for pn junction in.
It may be noted that the forward characteristics shifts upwards with increase in temperature. As we know, forward bias produces current through a diode and reverse bias essentially prevents current, except for a negligible reverse current. Vi characteristics of pn junction diode are as shown on the right side. A special type of pn junction diode that operates in reverse biased mode, more specifically in breakdown region is known as zener diode. Fig1 characteristics of diode with respect to temperature. In the beginning, by increasing the voltage the current change very slowly but when the voltage reaches 0. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse bias components equipments required. To draw the iv characteristic curve of a pn junction in forward bias and reverse bias physics lab manualncert solutions class 12 physics sample papers aim to draw the iv characteristic curve of a pn junction in forward bias and reverse bias. The vi characteristic of zener diode indicates that characteristic of zener diode in forward bias is same as pn junction diode.
Apparatus a zener diode with small reverse breakdown voltage of about 6 volts, i. Pn junction diode parameters like reverse saturation current, bias current, reverse breakdown voltage and barrier voltage are dependent on temperature. Pn junction diode baising and its vi characteristics elprocus. To draw the characteristic curve of a zener diode and to. With an increase in the voltage, the current also increases. The nonlinear, and polarity characteristics of the diode make for a very interesting and useful device albeit at the expense of added complexity of circuit design and analysis. 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.
To draw the iv characteristic curve of a pn junction in. The vi characteristics or voltagecurrent characteristics of the pn junction diode is shown in the below figure. Pn junction diode and characteristics of pn junction diode. Vi characteristics of zener diode the vi characteristics of a zener diode is shown in the below figure. The horizontal axis represents the voltage drop, the vertical axis the current. The zener diode is a particular type of diode that solves this problem. Zener diode definition, vi characteristics, and breakdown.
A pn junction diode is a twoterminal electronics element, which can be classified as either. The word diode can be explained as di means two and ode is obtained from electrode. J1 and j3 become reverse biased and the centre junction j2 becomes forward biased. The diode is two terminal non linear device whose iv characteristic besides exhibiting nonlinear behavior is also polarity dependent. Lets get a voltmeter and ammeter and connect it to the forward biased circuit of pn junction diode. We have seen that the diode can conduct only when it is forward biased and blocks when it is reversed biased. Static characteristics of junction diode, point contact diode and zener diode aim. Pn junction diode is one of the fundamental elements in electronics. Working of pn junction diode with biasing, characteristics. Whenever the voltage is applied to the diode then the anode terminal is made positive with respect to the cathode, j1 and j3 junctions are forward biased where j2 is reverse biased.
In this way a reverse biased pn junction may be regarded as parallel plate capacitor and thus the capacitance across this set up is called as the transition capacitance. Since a junction forms between a p type and n type material it is called as pn junction. Dec 23, 2017 experiment 15 to draw the i v characteristic curve of pn junction in forward bias reverse bias. Explain the effect of temperature on pn junction diode. Name quantity name quantity 1 diode by127, oa79 1one no each dc regulated power supply. Zener diode operates under the reverse bias in the breakdown region. Vi characteristics of pn junction diode in 3biasing modes elprocus. Apr 05, 2019 in this tutorial, we will learn about pn junction diodes and in particular the characteristics and working of pn junction diode. Similarly, when the diode is reversed biased, it acts as a perfect insulator with zero current through it. The lead connected to the ptype material is called the anode and the lead connected to the ntype material is the cathode. Useful mathematical relations are shown and illustrated with plots.
The vi characteristics of the ideal diode are shown in. Vi characteristics of pn junction diode in 3biasing modes. The diode has two terminals called a cathode and an anode. The diode is a device formed from a junction of ntype and ptype. A schottky junction is a special case of a pn junction, where metal serves the role of the ptype semiconductor. The primary difference between silicon and germanium diodes is the voltage needed for the diode to turn on or become forwardbiased. The width of depletion region alters with the external applied potential. To draw vi characteristic of pn junction diode and to determine knee or cut in voltage. For example, a common type of transistor, the bipolar junction transistor, consists of two pn junctions in series, in the form n pn or pn p. A schottky diode has a relatively low forward voltage drop and reverse recovery losses. This means that an led will pass current in its forward direction but block the flow of current in the reverse direction. Once that happens, large current flows through the junction and the diode may get destroyed. Pn junction diode characteristics explained in detail with graphs.
Experiment 15 to draw the i v characteristic curve of pn. Characteristics of photovoltaic solar cells analog. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light. This nonlinear characteristic illustrates that during the operation of the n junction, the resistance is not constant. The word varicap is originated from the combination of word variable and capacitor. The basics how diodes work working principle pn junction. What we are going to do is, vary the voltage across diode by adjusting the battery. 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. The effect of increased temperature on the characteristics curve of a pn junction diode is as shown in above figure. To draw the characteristic curve of a zener diode and to determine its reverse breakdown voltage. Pn junction diode characteristics experiment edunovus. Pn junction diode characteristics explained in detail. Voltampere vi characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. The doping level of the zener diode is somewhat higher than the normal pn junction diode.
This video lecture explains the vi characteristics of the zener diode. The slope of the pn junction diode in forwarding bias shows the resistance is very low. Jan 21, 2019 vi characteristics of pn junction diode. Pn junction diode characteristics electronic circuits and. Jan 02, 2019 once that happens, large current flows through the junction and the diode may get destroyed. Pn junction diode vi characteristics in forward and.
In this section, we will examine the relationship between the voltage and the current in the diode. Reverse bias prevents current as long as the reversebias voltage does not equal or exceed the breakdown voltage of the junction. The leakage current is higher than a pn junction diode. Apparatus a pn junction semiconductor diode, a 3 volt battery, a 50 volt. Rectifier circuits introduction we have studied the operation and iv characteristics of a pn junction diode in the previous experiment. 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. The pn junction supports unidirectional current flow. Pn junction diode baising and its vi characteristics. 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 and therefore we can not described its operation by simply using an equation such as. Thus if we kept the voltage constant, as we increase temperature the current increases. We operate a zener diode in reverse biased conditions, and this diode does not get damaged even when the voltage across this exceeds the reverse breakdown voltage.
The junction of n and p semiconductors is free of charge carriers. The vi characteristics of the ideal diode are shown in the figure below. This article discusses about pn junction diode, diode theory of zero bias, forward bias, reverse bias with vi characteristics and its applications. 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. Uniti diode current equation vi characteristics of 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. A simple circuit diagram is shown below, which has a pn junction diode, a battery in picture it is not shown as variable.
In zener diode, electric current flows from both anode to cathode and cathode to anode. To calculate its cut in voltage and forward resistance. The symbol of zener diode is similar to the normal pn junction diode, but with bend edges on the vertical bar. Now, if we join the two types of semiconductors ptype and ntype together then a new device is formed called as pn junction diode. Exp 1 study of different types of diode characteristics. A zener diode with small reverse breakdown voltage of about 6 volts, i. The diode is a device formed from a junction of ntype and ptype semiconductor material. Eee 4204 electronic i lab experiment no 01 name of the experiment. Pn junction is a significant building block and it is one among the indispensable structures. In this type of diode, we dope one side of a semiconductor piece with an acceptor impurity and another side with a donor impurity. What is the effect of temperature in the diode reverse characteristics. Characteristics of shockley diode the shockley diode comprises of three junctions namely j1, j2 and j3. It is a device whose capacitance changes with the variation in the applied reverse bias potential. Observation of characteristics of a zener diode debangshu mukherjee bs.
The iv characteristics of an led diode are similar to that of a regular diode except that the forward voltage may. The vi characteristic of scr, mosfet, led, pn junction diode, and zener diode is explained here. To plot the vi characteristics of a pn junction diode in forward bias condition. To study and verify the functionality of a pn junction diode in forward bias.
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