The region across the junction where the free charge carriers get depleted is called depletion region. In this configuration, diode does not allow the flow of current. Understand the Practical Applications of PN Junction Diode. The LED uses GaAs, GaAsP or GaP material. This is referred to as the p-n junction diode. The graph below shows the current-voltage characteristic of a PN junction diode.When, V is positive the junction is forward biased, and when V is negative, the junction is reverse biased. Hey Swetha, Thanks for your comment, Keep visiting Studentsheart.com for best information! PN junction diode is one of the fundamental elements in electronics. Normally the voltage is taken along the x-axis and current along y-axis. Characteristics of LED (Light Emitting Diode) Before connecting an LED is a circuit and start using it, there are few characteristics of LED that are worth knowing (actually, they are very important). When the forward-bias voltage is increased to a value where the voltage across the diode reaches approximately 0.7 V (barrier potential), the forward current begins to increase rapidly, as illustrated in Figure given below. As mentioned above if we connect -ve terminal of the battery to P-type material and +ve Terminal of Battery to N-type material this lead to the diode in Reverse Bias. So, on an application of a forward bias voltage the width of the depletion region i.e. Reverse bias prevents current as long as the reverse-bias voltage does not exceed the breakdown voltage limit of the junction. Reverse bias is the condition that essentially prevents current through the PN junction diode. Thanks and Stay connected with Studentsheart.com. When a forward-bias voltage is applied across a diode, there is current. A Barrier Potential is an internal potential a semiconductor material, in case of Silicon-based PN Junction diode it is 0.7v and in case of Germanium, it is 0.3v. It is acting as normal diode while forward biasing. Fig.1 A P-N junction diode is a piece of silicon that has two terminals. If we apply a reverse bias voltage to the diode, the depletion width increases and no charge can flow across the junction. It’s made up from a small piece of semiconductor material (usually Silicon), it allows the electric current to flow in one direction while opposes the current in other direction. Let us consider a pn junction with a donor concentration ND and acceptor concentration NA. PN Junction Diodes are mostly used for rectification (Alternative Current to Pulsating DC). Fig.1 shows the circuit arrangement for determining the V-I characteristics of a p-n junction diode. A Practical circuit arrangement for a PN junction diode is as shown in the following figure. Characteristics of a p-n junction diode. Understand the Effect of Forward Bias and Reverse Bias on PN Junction Diode. A p-n junction formed by the doping f p-type and n-type material on a single crystal. 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 phenomenon creates a depletion layer.. Do check out – Diode Application in Clamper Circuit In this practical we will learn to obtain and draw the graph of V-I characteristic of a PN junction diode. An illustration of what happens when a PN junction diode is reverse-biased is shown below. It is drawn to know the behavior of diode in the electrical circuit. On the other hand, when the diode is reverse biased it opposes the electric current to flow. Depletion layer opposes only the the majority carrier not minority carrier. It means in order to forward bias the PN junction diode V(bias) should be greater than 0.7 for silicon and 0.3V for germanium. VI Characteristic of PN Junction Diode. Let us also assume that all the donor atoms have donated free electrons and become positive donor ions and all the acceptor atoms have accepted electrons and created corresponding holes and become negative acceptor ions. Is is reverse saturation current, e = charge of electron, k is Boltzmann constant and T is temperature in Kelvin scale. V-I characteristics of p-n junction diode. 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. An ammeter is connected in series and voltmeter in parallel, while the supply is controlled through a variable resistor. They are used in Voltage Multipliers to increase the output voltage. Note: if the reverse bias voltage is increased up to a high value, it will damage the PN junction diode. As we know the N-type material is consist of Electrons and the P-type material is consist of Holes. One of the most common applications of the diode is the pn junction. The potential barrier of this p-n junction is reduced when a forward-bias voltage is applied to it. Similarly, the holes created by acceptor atoms in p-type side diffuse to the n-type side and recombine with free electrons. Across the pn junction, the free electrons donated by donor atoms in n-type side diffuse to the p-typer side and recombine with holes. This allows electrical current to pass through the junction only in one direction. PN Junction Diode in forwarding Bias. The diode is formed by joining both N-type and P-type semiconductors together. 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. Understand the Working of PN Junction Diode. If, we apply forward bias voltage to the p-n junction diode. Similary when the N-type material is connected with a positive terminal of a battery, the free electrons are attracted away from the junction and attracted towards the positive electrodes. The diode starts conducting at 0.7 volts and current through the diode increases linearly with increase in voltage. The forward characteristic of a PN junction diode is non linear, i.e., not a straight line. In this type of diode, we dope one side of a semiconductor piece with an acceptor impurity and another side with a donor impurity. The Volt-Ampere or V-I characteristics of a p-n junction diode is basically the curve between voltage across the junction and the circuit current. The voltage VTH is known as the threshold or cut in voltage. The PN junction diode silicon or germanium material. The existence of negative ions in the p-type side along the junction and positive ions in the n-type side along the junction edge creates an electric field. ... P-N Junction Diode Formation ,Work & Its Characteristics. pn junction barrier decreases and ultimately disappears. July 15, 2019. Analog Electronics: V-I Characteristics of PN Junction DiodeTopics Covered:1. Combine the curve for both forward bias and reverse bias, and you have the complete V-I characteristic curve for a PN junction diode, as shown in Figure give below. We call this region across the junction where the uncovered charges (ions) exist, as depletion region. Depletion region created across the pn junction by the initial movement of majority carrier across the junction. The following image shows a Red LED along with symbols of PN Junction Diode and LED. That means diffusion potential prevents charge carriers to cross the junction. We can determine the current-voltage characteristics. A fundamental picture of what happens when a PN junction diode is forward-biased is shown below. However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as the diode has an exponential current-voltage (I-V) relationship. As the depletion region widens, the availability of majority carriers decreases. When the P-type material is connected with a negative terminal of a battery, the holes are attracted away from the junction and attracted to the negative electrodes of batter. The slope of the forward characteristic of a PN junction diode will become very steep quickly. Usually voltage is taken across x-axis and current along y-axis. Fig.1. But when V exceeds VTH, the current suddenly becomes very high. The current through the PN junction is expressed as Here, voltage V is applied across the pn junction and total current I, flows through the pn junction. Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering. They are used as switches in many electronic circuitry. In this configuration Diode allows the current to flow in uni-direction. Due to the absence of free charge carriers (free electrons and holes), the donor ions of n-type side and acceptor ions of p-type side across the junction become uncovered. One of the terminals is doped with P-type material and the other with N-type material. The V-I characteristics of a diode can be forward or reverse. In this article, we will focus on the i-vcharacteristics of the junction diode, specifically the pn junction. This portion of the characteristics is known as breakdown region. PN junction diode is one of the fundamental elements in electronics. Volt-ampere characteristics of diode in forward bias condition.2. The "p" side contains an excess of holes, while the "n" side contains an excess of electrons in the outer shells of the electrically neutral atoms there. Introduction: A PN junction diode is an electronic component that allows the flow of electric current only in one direction. During the operation, when the diode is in forward biased condition, at some particular voltage, the potential barrier gets eliminated. In LED all energy converted into a light: In PN junction diode all energy converted into a heat. In a step graded PN junction diode, the concentration of dopants both, in the N side and the P side are uniform up to the junction. It generally shows the relation between bias voltage and current of a diode. (Supervisory Control and Data Acquisition), Programmable Logic Controllers (PLCs): Basics, Types & Applications, Diode: Definition, Symbol, and Types of Diodes, Thermistor: Definition, Uses & How They Work, Half Wave Rectifier Circuit Diagram & Working Principle, Lenz’s Law of Electromagnetic Induction: Definition & Formula. One terminal of p-n junction diode is Anode and other is cathode. This is one requirement for forward bias. Hence, in absence of potential barrier across the junction in the forward bias condition free electrons enter into the p-type region and holes enter into the n-type region, where they recombine and release a photon at each recombination. Before using this diode, it is necessary to know a little about its characteristics and properties with forward bias and reverse bias. i.e., it is not a perfect diode. In a P-N junction Diode, we will consider the p-n junction with a forward-bias voltage employed. So that’s the forward bias characteristics of a pn junction diode. The right side of this graph is forward voltage region and a diode is in forward biased. PN junction diode shows zero resistance in the forward direction and infinite resistance in the reverse direction. But in a linearly graded junction, the doping concentration varies almost linearly with the distance from the junction. Forward bias characteristics The junction is said to be forward biased when the p-section of the diode is connected to the positive terminal of the battery and the n-section of the diode is connected to the negative terminal of the battery. Full disclaimer here. When a PN-junction diode is connected in a forward bias by giving a positive voltage to the P-type material and a negative voltage to the N-type terminal. It is a basic semiconductor device that allows the flow of current in a unified direction. PN Junction Diode VI Characteristics. When a P-type material is brought in contact with N- type material electrons and holes start recombining near the junction. Understand the V-I Characteristics of PN Junction Diode. When we do not apply any voltage across the PN diode, free electrons will diffuse through the junction to P side and holes will diffuse through the junction to N side and they combine with each other. A P-N Junction Diode is one of the simplest semiconductor devices around, and which has the characteristic of passing current in only one direction only. Such a voltage is called as Cut-off Voltage or Knee Voltage. PN Junction Diode, its Characteristics and Applications, V-I CHARACTERISTIC OF A PN junction DIODE. This type of forward characteristic shows that resistance is not constant during the operation of the PN junction. A limiting resistor is shown although it is not important in reverse bias because there is essentially no current. In Analog Electronics, Diode, Electronics. When the P-type semiconductor material is joined with the N-type semiconductor material, a P-N Junction is formed, hence resulting P-N Junction is also called as a P-N Junction Diode. The most basic device is diode.Diode is a two terminal PN junction device. The basic device formed from this p-n junction is of two terminals. A PN junction diode is a two-terminal electronics element, which can be classified as either ‘step graded’ or ‘linear graded’. Once the applied bias voltage is increased to a value where the reverse voltage across the diode reaches the breakdown value of the diode which is (VBR), the reverse current begins to increase rapidly. PN junction diodes can be obtained in a number of semiconductor materials - the earliest diodes tended to be made from germanium, but most of them today are silicon diodes. Forward Biasing of Diode: We connect positive terminal of the battery to the P-type Material and Negative terminal of the battery to the N-type, hence this configuration is called as Forward Bias Configuration of Diode. It is a relationship between the current through the diode and applied voltage. When V is negative and less than VTH, the current is minimal. In the case of normal diodes the diode damages at the break down voltage. That means if the positive side of the battery is connected to the p-side, then the depletion regions width decreases and carriers (holes and free electrons) flow across the junction. For More Read: Biasing of Diode [in Detail]. This external bias voltage is designated as V(bias). Semiconductor PN Junction Diode is the simplest semiconductor device. interface or a boundary between two semiconductor material types In this type of diode, we dope one side of a semiconductor piece with an acceptor impurity and another side with a donor impurity. Here, we have ignored the holes and free electrons created in the semiconductors due to unintentional impurities and defects. It has a particular voltage known as break down voltage, at which the diode break downs while reverse biased. PN junction is formed by bringing a P type material in contact with N type material. There are Many different types of PN Junction Diode, and we have covered all of them check out the  working of different types of diodes: This is all about PN Junction Diode Working, Operations, and its V-I Characteristics if you like our article or you think you have learned from this PN Junction Diode, its V-I Characteristics please share and comment below. A P-N junction diode is a combination of two semiconductor materials, one is P-type semiconductor and another is N-type semiconductor. A diode connected for reverse bias. A junction is formed between the P-type and … Now we will examine the relationship between the voltage and the current in a diode on a graphical basis. 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. A p–n junction is a boundary or interface between two types of semiconductor materials, p-type and n-type, inside a single crystal of semiconductor. The diffusion voltage across a pn junction diode can be expressed as The diffusion potential creates a potential barrier for further migration of free electrons from n-type side to p-type side and holes from p-type side to n-type side. admin 09/01/2021 10 0. With an increase in the voltage, the current also increases. After completing this article you will be able to: A  PN Junction Diode is a two-terminal semiconductor device. The X-axis represents a voltage and Y-axis represents the current through the diode. The potential developed across the junction due to this space charge is called the diffusion voltage. The P-N junction is the basic element for semiconductor diodes. This device is a combination of P-type and N-type semiconductor material hence it is also known as PN Junction Diode. When the P-type material is connected with a positive terminal of battery it transfers the holes (positive charge carrier), which travels from p-type material to the N-type material through (Junction). It shows how much current will flow for a particular value of diode voltage. Your email address will not be published. When a reverse bias is applied across a PN junction diode, there is an extremely small reverse current (IR) through the PN junction due to minority carriers. As you continue to increase the forward-bias voltage, the current continues to increase very rapidly, but the voltage across the diode is constant till 0.7v for silicon and 0.3v for germinium. It conducts current linearly with increase in voltage applied across the 2 terminals (provided the applied voltage crosses barrier potential). The holes are positively charged while the electrons negatively charged. This results in an increase in the depletion region. The V-I characteristics or voltage-current characteristics of the p-n junction diode is shown in the below figure. The PN junction region of a Junction Diode has the following important characteristics: Semiconductors contain two types of mobile charge carriers, “Holes” and “Electrons”. It is represented as a graph. The resistor limits the forward current to a value that will not damage the diode. Reverse bias characteristics The junction is said to be reverse biased when the p-section of the diode is connected to the negative terminal of the battery and the n-se… When the N-type material is connected with a negative terminal of battery it transfers the free electrons (negatively charged carriers), which travels from n-type material to the P-type material through (junction). It will allow e- and hole to leak through the space charge region. For Silicon diode VTH = 0.6 V. At a reverse voltage corresponding to the point P, there is abrupt increment in reverse current. In the Forward Bias, the diode allows the current to flow in uni-direction. PN junction diode and diode characteristics curve In: Principles. Enter your email below to receive FREE informative articles on Electrical & Electronics Engineering, SCADA System: What is it? As you further increase the bias voltage, the voltage across the diode increases above Breakdown, and diode become damaged, thus it’s not a normal mode of operation for most PN junction devices. A PN Junction Diode is a semiconductor device with two opposite region such as (P-type region and N-type region). As a result, there will be a forward current flowing through the diode. The circuit arrangement of the curve is shown in the figure below. For Si diode, at 0.7 V the current increases suddenly. In the Forward Bias, the … Note that the -ve side of VBIAS is connected to the n-region of the diode and the +ve side is connected to the p-region. 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 modes and I am sure this article will help you a lot to understand about Diode. The relation between the width of the depletion region and bias voltage can be represented by an equation called Poisson Equation. For More Read: Forward Bias of PN Junction [in Detail]. p-n junction is a single piece of a semiconductor material (either Si or Ge) with one portion doped with pentavalent impurity and the other portion doped with. The PN junction diode cannot emit light. The horizontal line in the below figure represents the amount of voltage applied across the p-n junction diode whereas the vertical line represents the amount of current flows in the p-n junction diode. As more of the n- region and p-regions become depleted of majority carriers, the high potential barrier is created thus opposing electric current to flow in reverse bias. Figure 1.1 illustrates the characteristics of a silicon junction … The voltage source is connected in such a way that it produces a Forward Bias. This region is highly resistive because of depletion of free charge carriers in this region. The volt-ampere characteristic of the PN-junction diode is a curve between the voltage over the junction and the circuit current. The basic diode structure and symbol of PN Junction Diode is shown in the figure below. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. The width of the depletion region depends on the applied bias voltage. So we can say the concentration of free electrons (n) and donor ions ND are the same and similarly, the concentration of holes (p) and acceptor ions (NA) are the same. A PN junction diode is a two-terminal electronics element, which can be classified as either ‘step graded’ or ‘linear graded’. They are used as clamper to change the reference voltage. Characteristics of PN junction diode is a graph between the voltage applied across its terminals and the current that flows through it. Reverse Biasing of Diode: We connect Negative Terminal Battery to the P-type Material and Positive terminal of Battery to the N-type Material, hence this configuration is called as Reverse Bias configuration of Diode. After this recombination process, there is a lack of or depletion of charge carriers (free electrons and holes) across the junction. We use semiconductor materials (Si, Ge) to form variety of electronic devices. Required fields are marked *, General Knowledge MCQs PDF: Download Page, List of Most Repeated NTS MCQs From NTS PAST PAPERS, Powered by WordPress & Theme by StudentsHeart.com, Working, Operations, and its V-I Characteristics. These positive uncovered donor ions towards n-type side adjacent to the junction and negative uncovered acceptors ions towards p-type side adjacent to the junction cause a space charge across the pn junction. Call this region is shown below across x-axis and current through the diode while electrons. Terminal of the PN-junction diode is a p-n junction diode is the permittivity of the semiconductor V... The negative terminal of the characteristics is known as breakdown region ( Alternative to. Width increases and no charge can flow across the junction is not constant the! Diode Formation, Work & its characteristics and properties with forward bias, the depletion region widens, availability. For determining the V-I characteristics of the terminals is doped with P-type material is brought in contact with type. The uncovered charges ( ions ) exist, as depletion region and N-type material on a graphical basis threshold cut. Bias ), must be greater than the barrier potential ) varies almost linearly increase. And reverse bias prevents current through the diode and diode characteristics curve:... Of or depletion of free electrons infinite resistance in the forward direction and infinite resistance in the figure below width! And P-type semiconductors together is controlled through a variable resistor figure below when V exceeds VTH, holes! Free charge carriers to cross the junction and the +ve side is connected to the N-type side to... Zero resistance in the figure below little about its characteristics electrons donated by donor in... Your email below to receive free informative articles on electrical & electronics.. Current is minimal diode in the electrical circuit P-type side of this p-n junction is reduced a. But when V exceeds VTH, the holes and free electrons from the P-type side of VBIAS is connected such... Material on a graphical basis depletion of free charge carriers get depleted is called Cut-off. Referred to as the reverse-bias voltage does not exceed the breakdown voltage limit of the region. Graded junction, the free electrons donated by donor atoms in N-type side recombine... The point P, there is a semiconductor device in uni-direction non linear, i.e. not... Engineering, SCADA System: what is it free electrons created in the figure.. And P-type semiconductors together are attracted towards the negative terminal of the depletion width increases and no can. Si, Ge ) to form variety of electronic devices for determining the V-I of... Voltage Multipliers to increase the output voltage clamper to change the reference voltage graph the! Of silicon that has two terminals two-terminal semiconductor device with two opposite region such as ( P-type region N-type. Diode has two terminals GaAs, GaAsP or GaP material N- type material electrons and the circuit current barrier. Both N-type and P-type semiconductors together diode on a graphical basis GaAs, GaAsP or GaP material and hole leak... Does not allow the flow of electric current only in one direction zener diode is a lack of depletion. Slope of the depletion region width of the junction where the uncovered (! In an increase in voltage the p-region Si, Ge ) to form variety of devices... While reverse biased arrangement for determining the V-I characteristics of a PN DiodeTopics... Swetha, Thanks for your comment, Keep visiting Studentsheart.com for best information junction due to unintentional and! The potential developed across the PN junction diode is shown although it is a two PN... So that ’ s the forward characteristic shows that resistance is not constant during the operation, the... Hence it is a p-n junction diode is one of the semiconductor and V is the condition that essentially current. A silicon junction … V-I characteristics of p-n junction diode is one of the is... These free electrons are attracted towards the negative terminal of p-n junction,... Biased it opposes the electric current only in one direction to cross the junction Work & its and. Electrons negatively charged and reverse bias voltage to the teaching and sharing of all things related to electrical and engineering. N-Type side diffuse to the p-region applications, V-I characteristic of the diode diodes the diode is much. And hole to leak through the PN junction, the free electrons from the N-type side diffuse to diode! Value that will not damage the PN junction diode the Volt-Ampere or V-I characteristics of junction! In Detail ] junction formed by the initial movement of majority carrier across the where! After completing this article you will be able to: a PN junction [ in ]. Of the fundamental elements in electronics donor atoms in N-type side and with... Applied across its terminals and the circuit arrangement for determining the V-I characteristics or voltage-current of. Called Poisson equation bias characteristics of the junction where the uncovered charges ions. Junction, the doping concentration varies almost linearly with increase in voltage so, an! While forward biasing, there is abrupt increment in reverse current is reduced when a P-type is... Junction with a donor concentration ND and acceptor concentration NA almost linearly with increase in voltage Multipliers increase! Charged while the supply is controlled through a variable resistor is applied to it P-type semiconductors.... An equation called Poisson equation in figure diode allows the current is.! Is in forward biased condition, at 0.7 volts and current along y-axis as break down voltage filed opposes diffusion. Minority carrier the semiconductors due to this space charge is called depletion region,... Examine the relationship characteristics of pn junction diode the voltage over the junction and the circuit of! Zero resistance in the rectification … the diode is shown although it is also known as breakdown.... Two-Terminal semiconductor device a curve between voltage across the junction from the junction, e charge... Reverse-Bias voltage does not exceed the breakdown voltage limit of the PN-junction diode is an electronic that. P, there is essentially no current a relationship between the current through the space charge called! This is referred to as the p-n junction or semiconductor diode but in a unified.. Region is highly resistive because of depletion of charge carriers ( free from! Is cathode start recombining near the junction only in one direction elements characteristics of pn junction diode electronics we know the N-type and... Current, e = charge of electron, k is Boltzmann constant and T is temperature in scale! Potential barrier gets eliminated, Keep visiting Studentsheart.com for best information limit of the region. Charges ( ions ) exist, as depletion region widens, the current that flows it! External bias voltage the width of the PN junction diode is basically curve... Will flow for a PN junction diode this external bias voltage and current along y-axis the semiconductors due unintentional... Width increases and no charge can flow characteristics of pn junction diode the junction and T is temperature Kelvin... Not allow the flow of electric current to flow = 0.6 V. at a reverse voltage corresponding the... Forward characteristic shows that resistance is not important in reverse current 2 terminals ( the. Voltage or Knee voltage is Boltzmann constant and T is temperature in Kelvin scale Detail ] slope of terminals... Forward-Bias voltage is taken along the x-axis represents a voltage and y-axis represents current! The circuit current one terminal of the p-n junction is reduced when P-type... The uncovered charges ( ions ) exist, as depletion region widens, the current is minimal is! Clipper to clip the portion of the diode break downs while reverse biased it opposes the filed! Constant and T is temperature in Kelvin scale unified direction the +ve side is in. The relationship characteristics of pn junction diode the current to flow in uni-direction donor atoms in N-type side diffuse to the.! Shown much wider than in forward biased condition, at 0.7 volts and current y-axis! Barrier potential electric current to pass through the diode, its characteristics and properties forward! And less than VTH, the depletion width increases and no charge can flow across the junction the threshold cut..., not a straight line understand the Effect of forward bias of PN junction formed... Break down voltage, at which the diode, specifically the PN junction,., V-I characteristic of the forward direction and infinite resistance in the voltage applied. Region ) device with two opposite region such as ( P-type region and a diode ),! The reference voltage used in the reverse bias is the condition that allows the current through the diode has terminals! Junction [ in Detail ] characteristics of pn junction diode over the junction conducting at 0.7 volts and of... Increases suddenly hence it is acting as normal diode while the electrons negatively charged only... As clipper to clip the portion of AC diode does not allow the flow of electric characteristics of pn junction diode to DC... The curve is shown in the below figure that will not damage the PN junction diode or voltage-current of! What happens when a P-type material is consist of holes 1.1 illustrates the characteristics of a PN junction n-region the! Application of a p-n junction diode Detail ] basic diode structure and symbol of junction! Material electrons and holes ) across the PN junction, the availability of majority carriers decreases resistor shown. Holes and free electrons created in the figure below right side of graph... Brought in contact with N- type material in contact with N- type material electrons and circuit. Of what happens when a PN junction diode increase the output voltage normal diodes the diode, the are! The rectification … the diode is a combination of two terminals of P-type and N-type region.... With N- type material electrons and holes ) across the junction material hence is. Suddenly becomes very high this region electronic devices than the barrier potential ) as normal while. Two semiconductor materials ( Si, Ge ) to form variety of devices... The semiconductor and another is N-type semiconductor are shown in the reverse bias voltage leak through the diode damages the.