By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -13 Light Emitting Diode & Tunnel Diode.

Slides:



Advertisements
Similar presentations
Semiconductors Chapters
Advertisements

THE LIGHT EMITTING DIODE
Physics of Semiconductor Devices. Formation of PN - Junction When a P-type Semiconductor is joined together with an N-type Semiconductor a PN junction.
Diodes Benchmark Companies Inc PO Box Aurora CO
Semiconductors and Diodes
Unit-II Physics of Semiconductor Devices. Formation of PN Junction and working of PN junction. Energy Diagram of PN Diode, I-V Characteristics of PN Junction,
SPECIAL DIODES P. SYAM SUNDAR ASSOCIATE PROFESSOR DEPT. OF ECE K L UNIVERSITY.
By Squadron Leader Zahid Mir CS&IT Department , Superior University
ZENER DIODE / BREAKDOWN DIODE
Characteristics, Structures, and Applications.  Description of LED and Infrared LED  Schematic Symbol  Structure  Function and Characteristics  Application.
Special-Purpose Diodes
1 SEMICONDUCTOR Diodes PN junction and diode biasing Diodes PN junction and diode biasing.
By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -05 Diode Biasing.
By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -21 Field Effect Transistor.
By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -14 Transistors.
Chapter 4. Diodes. Copyright  2004 by Oxford University Press, Inc. Diode Simple non-linear device 2 terminal device, uni- or bi-directional current.
Series Connection Series Connection Requires more voltage The supply voltage should be the sum of the rated voltage required for LED.
Electronic Devices and Circuit Theory
Chapter 1 : Diodes Gopika Sood Assistant Professor in Physics
Kristin Ackerson, Virginia Tech EE Spring The diode is the simplest and most fundamental nonlinear circuit element. Just like resistor, it has.
SEMICONDUCTOR DEVICES. Diodes as a semiconductor devices Symbol and Structure Diodes is made by joining p-types and n- types semiconductor materials.
Introduction To Semiconductors
Semiconductors. A semiconductor is a material whose resistance is between that of a conductor and an insulator. Eg Silicon.
Semiconductor Devices In a typical audio system, diodes are used in the power supply to create a dc voltage from the ac voltage present at the wall socket.
BEX100 - Basic Electricity SemiconductorsDiodes. Unit Objectives: Understanding the materials that make up a basic diodeUnderstanding the materials that.
29P Electron Isolated copper Atom Conductor Valence orbit has only one Electron and is loosely bound to core Core.
Intro to Semiconductor devices & Diodes Electronics 1 CVHS.
Chapter 1: Semiconductor Diodes. Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Electronic Devices.
Semiconductor Introduction ENGI 242 ELEC 222. January 2004ENGI 242/ELEC 2222 Specification Symbol Notation Standard Type of valueSymbolSubscript Instantaneous.
Electronics Devices and Circuit Theory 10th Edition - Boylestad Electronics Fundamentals 8 th edition - Floyd/Buchla Majority and Minority Carriers Majority.
Ping Hsu Buff Furman John Luk 21SEP2010
Band Theory of Solids In isolated atoms the electrons are arranged in energy levels.
Chapter 1: Semiconductor Diodes. Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Electronic Devices.
Conductors – many electrons free to move
AELE237Semiconductor Materials1 Semiconductor Materials and pn Junctions T. Floyd, “Electronic Devices”, Maxwell Macmillan International Editions, Chapter.
1 Higher Physics Unit 3 Optoelectronics Semiconductors.
Physics of Semiconductor Devices
Introduction to Semiconductors
SMART LIGHTING Diodes K. A. Connor Mobile Studio Project Center for Mobile Hands-On STEM SMART LIGHTING Engineering Research Center ECSE Department Rensselaer.
Diodes and Diode Applications Topics Covered in Chapter : Semiconductor Materials 27-2: The PN Junction Diode 27-3: Volt-Ampere Characteristic Curve.
PRACTICAL # 11 Introduction to light emitting diode (LED), its working principle and terminal identification By:Engr.Irshad Rahim Memon.
By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -04 PN Junction.
Problems All problems up to p.28 Q 4 can be done.
Based on current conduction, materials are classifieds as 1)Insulators Ex: Wood, Mica, Diamond 2) Conductors Ex: Copper, Aluminium 3) Semiconductors Ex:
Semiconductors – Learning Outcomes
Semiconductors. O A Semiconductor is a material whose resistivity is between that of a good conductor and a good insulator. O Examples of materials which.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. MALVINO & BATES SEVENTH EDITION Electronic PRINCIPLES.
Robert Boylestad Digital Electronics Copyright ©2002 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Chapter 1: Semiconductor.
1)SEMICONDUCTOR DEVICES 2)WORKING PRINCIPLE OF DIODE AND SPECIAL DIODE Birla Vishwakarma Mahavidyalaya Branch: Electronics and Telecommunication Branch.
Chapter 3 Special-Purpose Diodes
Electronics Technology Fundamentals Chapter 17 Introduction to Solid State Components: Diodes.
ELECTRONICS. FUNDAMENTALS OF ELECTRONICS ELECTRONICS Electronics is the branch of physics which deals with development of electron-emitting devices, there.
College Name : Shree Swami Atmanand Saraswati Institute Of Technology(SSASIT)(076) Year : 2 nd year(3 rd sem) EC-2015 Subject Name : Electronic Devices.
Electronics Fundamentals
DIODES AND APPLICATIONS
INTRODUCTION TO SEMICONDUCTORS
Physics of Semiconductor Devices
Other diodes Electronic device and circuit Active learning assignments
Physics of Semiconductor Devices Mr. Zeeshan Ali, Asst. Professor
BIRLA VISHWAKARMA MAHAVIDHYALAYA
Chapter 1: Semiconductor Diodes
Parul Institute of Engineering & Technology
Government Engineering College, Bhavnagar.
Part -3 Diode characteristics
Electronics Fundamentals
Semiconductors Chapter 25.
Electronic Fundamental Muhammad Zahid
Semiconductor Diodes Chapter 1 Boylestad Electronic Devices and Circuit Theory.
Solid state electronics ece-1109
Presentation transcript:

By Squadron Leader Zahid Mir CS&IT Department, Superior University PHY-BE -13 Light Emitting Diode & Tunnel Diode

LED Operating Principle When the device is forward-biased, electrons cross the pn-junction from the n-type material and recombine with the holes in the p-type material. When the recombination takes place, the recombining electrons release energy in the form of heat and light. This process is known as “electroluminescence”.

LED

LED Symbol

Various impurities are added during the doping process to establish the wavelength of the emitted light (i.e the color of light). LED Semiconductor Material – Gallium Arsenide (GaAs)(emit infrared radiation) – Gallium Arsenide Phosphate (GaAsP) (red or yellow light) – Gallium Phosphate (GaP)(red or green light)

LED Biasing The forward voltage across an LED is considerably greater than for a silicon diode (typically the maximum V f for LED is between 1.2V and 3.2V). Reverse breakdown for an LED is much less than for a silicon rectifier diode (3V to 10V).

Light Output The LED emits light in response to a sufficient forward current. The amount of power output translated into light is directly proportional to the forward current.

Application Seven-Segment Display – Combinations of the segments form the ten decimal digits. – Each segment in the display is an LED. – By forward-biasing selected combinations of segments any decimal digit and decimal point can be formed.

Tunnel Diode

It shows a special characteristic known as negative resistance. It is constructed with germanium or gallium arsenide by doping the p and n regions much more heavily than in a conventional rectifier diode. This heavy doping results in an extremely narrow depletion region. The heavy doping allows conduction for all reverse voltages so there is no breakdown effect as with the conventional rectifier diode.

Tunnel Diode The extremely narrow depletion region permits electrons to “tunnel” through the pn junction at very low forward- bias voltages, and the diode acts as a conductor (point A & B). At point B, the forward voltage begins to develop a barrier, and the current begins to decrease as the forward voltage continues to increase. This is the negative-resistance region; R F = ΔV F / ΔI F At point C, the diode begins to act as a conventional forward-biased diode.