The capacitance measurement will be performed on a speci c parameter analyzer. Pn junction diode and diode characteristics electronicstutorials. Lab 2 pn junction diode characteristic prelab objective. The pn junction biasing the pn junction the diode trouble shooting. The lead connected to the ptype material is called the anode and the lead connected to the ntype material is the cathode. Semiconductor physics semiconductors and diodessemiconductors. To study and verify the functionality of pn junction diode as series and shunt clippers. Jan 07, 2016 pn junction diode experiment using breadboard and simple components duration. In forward bias condition, current is constant until certain voltage is reached. Pn junction diode in the reversebiased configuration is sensitive to light from a range between 400nm to nm, which includes visible light.
Semiconductor, silicon, pn junction, forward bias, reverse bias, diode. Scribd is the worlds largest social reading and publishing site. To draw the vi characteristic of zener diode and to determine zener breakdown voltage. To measure the effect of forwardbiased and reversedbiased on current in a junction diode. Electrons and holes diffuse from areas of high concentration toward areas of low concentration. Jan, 2015 pn junction diode characteristics lab expriment 1. While doing the experiment do not exceed the readings of the diode. The pn junction is a versatile element, which can be used as a. If an external potential is applied to the terminals of pn junction, it will alter the potential between the p and nregions. Zero bias no external voltage potential is applied to the pn junction diode.
It is the most essential and the basic building block of the electronic device. 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. In the previous tutorial we saw how to make an ntype semiconductor material by doping a silicon atom with small amounts of antimony and also how to make a ptype semiconductor material by doping another silicon atom with boron. 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. To plot voltampere characteristics of silicon pn junction diode. Pdf experiment on the physics of the pn junction researchgate. A pn junction consists of two semiconductor regions with opposite doping type as shown in figure. Pn junctions consist of two semiconductor regions of opposite type. To find cutin voltage for silicon pn junction diode. Pn junction diode baising and its vi characteristics.
Simulator procedure as performed through the online labs select the characteristics of diode from the drop down list. Pdf experiment on the physics of pn junction giacomo. Experiment 16 the pn junction introduction in this experiment on the physics of the pn junction, a determination is made of both the universal constant ek i. I recently performed this experiment in the solid states lab during the ii semester for m. 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. Working of pn junction diode with biasing, characteristics. It acts as a diode, which can serve in electronics as a rectifier, logic gate, voltage regulator zener diode, switching or tuner varactor diode. By exploring the electrical properties of silicon, it is possible to acquire an understanding of the inner workings of the pn junction. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse bias components equipments required. The pn junction diode is a twoterminal device, which is formed when one side of the pn junction diode is made with ptype and doped with the ntype material. The semiconductor diode is formed by doping ptype impurity in one side and ntype of impurity in another side of the semiconductor crystal forming a pn junction as shown in the following figure.
Connecting a pn junction to an external voltage source is biasing a pn 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. Introduction a simple experiment on the physics of the pn junction may be carried out in undergraduate laboratory courses, providing a determination of both the universal constant ek i. Physics 176 university physics lab ii experiment 7 the pn. Physics of semiconductor devices pn junction depletion width problem a silicon pn diode has a doping of n d 81015 1 cm3 and n a 210 16 1 cm3. Measurements of temperature and voltage will be done using a thermocouple and an ad converter respectively. Simulator procedure as performed through the online labs select the characteristics of diode from the. Iv characteristics pn junction diode forward biasing a pn junction the diode is said to be forward biased when the positive terminal of the battery is connected to anode and negative terminal to cathode. Characteristics of capacity for pn junction and pn schottky theory. What is forward bias and reverse bias in a pn junction. To plot characteristics between reverse saturation current and 10 3t and find out the approximate value of energy band gap in pn junction diode apparatus. Pn junction diode experiment using breadboard and simple components duration.
Such junctions show a pronounced rectifying behavior. A suitable positive voltage forward bias applied between the two ends of the pn junction can supply the free electrons and holes with the extra energy. When positive terminal of the external supply is connected to p region and. This may cause the diode to become shorted and will result in the flow of maximum circuit current, and this shown as a step downward slope in the reverse static characteristics curve below. If the doping levels are increased to 1 in 10 3, the depletion layer width is of the order of 10 nm. Ideal diode iv curve and symbol in the above graph, the threshold voltage i. Vi characteristics of pn junction diode in 3biasing modes. Pn junction diode is symbolically represented as shown in picture. The pn junction is the fundamental building block of the electronic age. Shockley model from sze, 1981 vv at 1 j j e tot s n n p p p n s l d n q l d p j 0 0 j j x j x tot n p p n a i n n n d n q 2 w p n. The pside or the positive side of the semiconductor has an excess of holes and the nside or the negative side has an excess of electrons. We were supposed to study the material characteristics of a pn junction diode, like i reverse saturation current, is and material constant, n ii energy band gap, eg iii depletion layer capacitance, cd. Tunnel diode working principle and characteristics ece.
Forward bias current flows reverse bias no current flow. If a suitable positive voltage forward bias is applied between the two ends of the pn junction, it can supply free electrons and holes with the extra energy they. The following task will acquaints us with the characteristics of a nonlinear devise the diode. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse. Pnjunction material characterisitcs experiment lab. A pn junction is an interface or a boundary between two semiconductor material types, namely the ptype and the ntype, inside a semiconductor. 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. Plot a graph with reverse voltage along x axis and reverse current along y axis. The pn junction forms the basis of the semiconductor diode. The pnjunction is the root for semiconductor diodes. The pn junction the pn junction is a homojunction between a ptype and an ntype semiconductor.
Zener diode, voltmeter 02volt, voltmeter 030 volt, miliammeter, microammeter, variable source 02 volt and 030 volt. Fit the capacitance with the step junction model and calculate the zero bias junction capacitance cj0a. Temperature dependence of the saturation current of a junction diode scope the determination of the temperature dependence of the saturation current in reverse biased pn junction diodes silicon and germanium in order to determine the dominant contribution to the saturation current. Function generator, oscilloscope, power supply, vom, digital multimeter. The direction of arrow is the direction of conventional current flow under forward bias. Simulate in pspice the iv characteristic for d1n4002 pnjunctionrectifier diode. Definition ptype semiconductor is suitably joined to ntype semiconductor,to conduct surface is called pn junction. To determine experimentally and graph the volt ampere characteristics of a junction diode.
Dont feel bad if you havent studied pn junctions before. E o is the zero bias junction voltage, v t the thermal voltage of 26mv at room temperature, n d and n a are the impurity concentrations and n i is the intrinsic concentration. Objective the objective of this experiment is to measure the iv curve for pn junction diode and to understand the characteristics of pn junction. Under these conditions, the holes in pregion are repelled by the. The pn junction is the root for semiconductor diodes. For the analysis of the accumulated data we shall use a spreadsheet. Thus, electrons diffuse from the nregion to the pregion. This simulation will give you an idea of the voltage and current values to be measured in the lab. What are the depletion width in the nregion, the depletion width in the pregion, and the builtin potential at 300k. The objective of this experiment is to measure the iv curve for pn junction diode and to understand the characteristics of pn junction. 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 diode, voltmeter 02volt, voltmeter 030 volt, miliammeter, micro ammeter, variable source 02 volt and 030 volt. Figure 1 at the junction initially free charge carriers. Diodes explained the basics how diodes work working.
Coed school kolar road bhoapl department of physics project report investigatoryproject on pn junction and diodes project report submitted by govind patel submitted to mrs ratna hajela. Silicon a single silicon atom consists of fourteen negatively. Diodes, bipolar junction transistors and mos characterization contents 1 introduction 1 2 materials 1. Experiment 1 vi characteristics of diode 1 vi characteristics of diode aim.
One final point, if the reverse bias voltage vr applied to the diode is increased to a sufficiently high enough value, it will cause the diodes pn junction to overheat and fail due to the avalanche effect around the junction. The dopants are assumed to be shallow, so that the electron hole density in the ntype ptype region is. A pn junction is formed when an ntype material is fused together with a ptype material creating a semiconductor diode. Forward biasing a pn junction diode is very simple. However, in real experiment in the lab this circuit. Pnjunction material characterisitcs experiment lab manual. In such a pn junction tunneling effect is significant, such pn junction devices are called tunnel diodes. The maximum energy that an electron in a metal has at the absolute zero temperature is called the fermi level of energy. The region on the left is ptype with an acceptor density na, while the region on the right is ntype with a donor density nd.
You can check out and keep the portable breadboards, vb106 or vb108, from the 111lab for yourself only one each please this is the first of three labs on basic semiconductor components. Energy band gap apparatus containing micrometer, voltmeter, temperature controlled electric oven to heat up the diode, pn junction. Lab report zener diod free download as powerpoint presentation. Physics of semiconductor devices pn junction depletion. Now lets try applying an external voltage to the pn junction diode. When an intimate connection between the semiconductor ntype and ptype, the electrons are transfer from ntype to ptypedue to charge carrier diffusion from high concentration to low concentration. Name quantity name quantity 1 diode by127, oa79 1one no each dc regulated power supply. A pn junction is the metallurgical boundary between the n and pregions of a semiconductor crystal. They are also called pn diodes in analogy with vacuum diodes. Shockley model from sze, 1981 vv at 1 j j e tot s n n p p p n s l d n q l d p j 0 0 j j x j x. In general, the cathode of a diode is marked by a solid line on the diode. Diode pn junction when p and n type silicon are brought together during manufacture, a junction is created where the p type and n type materials meet, and holes close to the junction in the p type silicon are attracted into negatively charged n type material at the other side of the junction.
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