Lect. 10: Photodetectors

Size: px
Start display at page:

Download "Lect. 10: Photodetectors"

Transcription

1 Photodetection: Absorption => Current Generation h Currents Materials for photodetection: E g < h Various methods for generating currents with photo-generated carriers: photoconductors, photodiodes, avalanche photodiodes

2 Photon energy (ev) (m -1 ) Si a-si:h Ge In 0.7 Ga 0.3 As 0.64 P 0.36 In 0.53 Ga 0.47 As GaAs InP - Sharp decrease in for >E g - Photodetection for indirect bandgap materials? Wavelength (m)

3 - Photodetection for indirect bandgap materials? E E CB E c CB Indirect Bandgap, E g Direct Bandgap E g Photon E v Photon E c VB VB E v Phonon k k k k (a) GaAs (Direct bandgap) (b) Si (Indirect bandgap) Unlike emission, absorption in indirect bandgap semiconductor is highly probable

4 Photodetection efficiency I R (Responsivity) P I q (Quantum Efficiency) = P h q 1.24 R h [ev] h [ m] Rq[ C] [1/ V] 1.24[ ev ] 1.24 Responsivity (A/W) Ideal Photodiode QE = 100% ( = 1) Si Photodiode g Wavelength (nm)

5 Photoconductor Without light, w d Conductivity: qen qhp ( : electron, hole mobility) J eh, E I V wd n 0, p 0 With light, I + v - n n n, p p p 0 0 R? q ( nn) q ( p p) e V V I wd wdqenqhp h 0

6 With light, d nn0 n, p p0 p qe( nn) qh( p0 p) w n, p V V I wd wdqenqhp + v - I P npint (Assume n, p are uniform) h wd V P V P I wd wd qe hint = qe hint V 2 h wd h I I q R (Assume dark current is small) e hint V P 2 P h q R G where G int e h V 2 h

7 h+ e Photoconductor I ph Gain: G e h V 2 Assuming e h, G e V 2 2 = e e V e ; Time for travelling distance V e E v e e ==> electrons circulate many time before recombination With h G ( ) V 2 = e h eh eh V ( ) ( ) E v v e h e h e h 1 1 e h ve vh 1 1 ( e h) e h

8 d Photoconductors: I n, p + v - w - Very easy to make - arge gain - But slow (speed limited by - Can have significant dark currents

9 Faster, less dark-current photodetectors? photodiode p n B - h + As + PN junction in reverse bias e - No significant current flow=> small dark currents E (x) W p M 0 W n x - Photo-generated carriers are removed by built-in field in depletion region (space charge region) E o

10 P N - Photo-generated carriers drift into P (holes) and N (electrons) regions generating currents I int P q h E (x) E o W p M 0 W n x - One photon creates a pair of electron and hole - Problem: depletion region is very thin (< 1 m) int is very small => Use PIN structure

11 SiO 2 Electrode p + Electrode (a) i-si n + net en d (b) x PIN Photodiode en a E(x) (c) x E o W h > E g (d) E h+e I ph R V out V r

12 PD with gain? Avalanche Photodiode (APD) (avalanche: a large mass of snow, ice, earth, rock, or other material in swift motion down a mountainside) Achieve gain by multiplying electrons and/or holes. Impact Ionization: Under high E-field, electrons and holes can have sufficiently high kinetic energies breaking bonds and creating new e-h pairs. E h + e E e It is preferred only one type of carrier (either electron or hole) causes impact E Ionization v E c n + p Avalanche region š h + : ratio of ionization coefficients (= hole/electron)

13 Metal-Semiconductor-Metal (MSM) Ge PD ow responsivity due to metal shadow (surface illuminated type) arge dark current (low schottky barrier, quality of Ge grown on Si) Electrode distance photodetection bandwidth Type Responsivity OE bandwidth Dark current Ge thickness WG MSM V 40 -2V 90 -1V 100 nm Ref) 2010, OE, CMOS-integrated high-speed MSM germanium waveguide photodetector, IBM

14 Vertical PIN Ge PD Thickness of intrinsic Ge: tradeoff between transit time and junction cap RC time and transit time photodetection bandwidth E-field Type Responsivity OE bandwidth Dark current Ge thickness WG Vertical PIN V 50 -1V 50 -1V 400 nm Ref) 2015, JT, High-responsivity low-voltage 28-Gb/s Ge p-i-n photodetector with silicon contacts, IMEC

15 ateral PIN Ge PD ower minority carrier diffusion length increase photodetection bandwidth Type Responsivity OE bandwidth Dark current Ge thickness WG ateral PIN > 1 -1V > 70 -1V V 500 nm Ref) 2015, OE, High bandwidth, high responsivity waveguide-coupled germanium p-i-n photodiode, IHP

16 Separate-Absorption-Charge-Multiplication (SACM) PD (Ge/Si APD) Si s low noise property & Ge s strong absorption near 1.55 μm wavelength ow k eff (k ~ 0.09, ratio of ionization coefficients of electrons and holes) high gain-bandwidth products, low noise Need large reverse bias for avalanche high dark current Bias Type Responsivity OE bandwidth Dark current Ge thickness WG SACM APD V V V 1 μm Ref) 2013, OFC, High speed waveguide-integrated Ge/Si avalanche photodetector, IME

Photodetector. Prof. Woo-Young Choi. Silicon Photonics (2012/2) Photodetection: Absorption => Current Generation. Currents

Photodetector. Prof. Woo-Young Choi. Silicon Photonics (2012/2) Photodetection: Absorption => Current Generation. Currents Photodetection: Absorption => Current Generation h Currents Materials for photodetection: E g < h Various methods for generating currents with photo-generated carriers: photoconductors, photodiodes, avalanche

More information

Photodetector Basics

Photodetector Basics Photodetection: Absorption => Current Generation hυ Currents Materials for photodetection: t ti E g

More information

LEC E T C U T R U E R E 17 -Photodetectors

LEC E T C U T R U E R E 17 -Photodetectors LECTURE 17 -Photodetectors Topics to be covered Photodetectors PIN photodiode Avalanche Photodiode Photodetectors Principle of the p-n junction Photodiode A generic photodiode. Photodetectors Principle

More information

Lecture 12. Semiconductor Detectors - Photodetectors

Lecture 12. Semiconductor Detectors - Photodetectors Lecture 12 Semiconductor Detectors - Photodetectors Principle of the pn junction photodiode Absorption coefficient and photodiode materials Properties of semiconductor detectors The pin photodiodes Avalanche

More information

Chapter 4. Photodetectors

Chapter 4. Photodetectors Chapter 4 Photodetectors Types of photodetectors: Photoconductos Photovoltaic Photodiodes Avalanche photodiodes (APDs) Resonant-cavity photodiodes MSM detectors In telecom we mainly use PINs and APDs.

More information

OPTI510R: Photonics. Khanh Kieu College of Optical Sciences, University of Arizona Meinel building R.626

OPTI510R: Photonics. Khanh Kieu College of Optical Sciences, University of Arizona Meinel building R.626 OPTI510R: Photonics Khanh Kieu College of Optical Sciences, University of Arizona kkieu@optics.arizona.edu Meinel building R.626 Announcements Homework #6 is assigned, due May 1 st Final exam May 8, 10:30-12:30pm

More information

Photosynthesis & Solar Power Harvesting

Photosynthesis & Solar Power Harvesting Lecture 23 Semiconductor Detectors - Photodetectors Principle of the pn junction photodiode Absorption coefficient and photodiode materials Properties of semiconductor detectors The pin photodiodes Avalanche

More information

Photonic Communications Engineering Lecture. Dr. Demetris Geddis Department of Engineering Norfolk State University

Photonic Communications Engineering Lecture. Dr. Demetris Geddis Department of Engineering Norfolk State University Photonic Communications Engineering Lecture Dr. Demetris Geddis Department of Engineering Norfolk State University Light Detectors How does this detector work? Image from visionweb.com Responds to range

More information

Photodetectors Read: Kasip, Chapter 5 Yariv, Chapter 11 Class Handout. ECE 162C Lecture #13 Prof. John Bowers

Photodetectors Read: Kasip, Chapter 5 Yariv, Chapter 11 Class Handout. ECE 162C Lecture #13 Prof. John Bowers Photodetectors Read: Kasip, Chapter 5 Yariv, Chapter 11 Class Handout ECE 162C Lecture #13 Prof. John Bowers Definitions Quantum efficiency η: Ratio of the number of electrons collected to the number of

More information

1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00

1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00 1 Name: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND Final Exam Physics 3000 December 11, 2012 Fall 2012 9:00-11:00 INSTRUCTIONS: 1. Answer all seven (7) questions.

More information

Electron Energy, E E = 0. Free electron. 3s Band 2p Band Overlapping energy bands. 3p 3s 2p 2s. 2s Band. Electrons. 1s ATOM SOLID.

Electron Energy, E E = 0. Free electron. 3s Band 2p Band Overlapping energy bands. 3p 3s 2p 2s. 2s Band. Electrons. 1s ATOM SOLID. Electron Energy, E Free electron Vacuum level 3p 3s 2p 2s 2s Band 3s Band 2p Band Overlapping energy bands Electrons E = 0 1s ATOM 1s SOLID In a metal the various energy bands overlap to give a single

More information

Course overview. Me: Dr Luke Wilson. The course: Physics and applications of semiconductors. Office: E17 open door policy

Course overview. Me: Dr Luke Wilson. The course: Physics and applications of semiconductors. Office: E17 open door policy Course overview Me: Dr Luke Wilson Office: E17 open door policy email: luke.wilson@sheffield.ac.uk The course: Physics and applications of semiconductors 10 lectures aim is to allow time for at least one

More information

ECEN 5645 Introduc0on to Optoelectronics Class Mee0ng 25. Non- PIN Solid State Detectors

ECEN 5645 Introduc0on to Optoelectronics Class Mee0ng 25. Non- PIN Solid State Detectors ECEN 5645 Introduc0on to Optoelectronics Class Mee0ng 25 Non- PIN Solid State Detectors Today s Topics Avalanche Photodiodes Problem 5.6 APD Numerics and Examples Heterojunc0on Detectors Problem 5.10 Quantum

More information

Single Photon detectors

Single Photon detectors Single Photon detectors Outline Motivation for single photon detection Semiconductor; general knowledge and important background Photon detectors: internal and external photoeffect Properties of semiconductor

More information

Auxiliaire d enseignement Nicolas Ayotte

Auxiliaire d enseignement Nicolas Ayotte 2012-02-15 GEL 4203 / GEL 7041 OPTOÉLECTRONIQUE Auxiliaire d enseignement Nicolas Ayotte GEL 4203 / GEL 7041 Optoélectronique VI PN JUNCTION The density of charge sign Fixed charge density remaining 2

More information

MTLE-6120: Advanced Electronic Properties of Materials. Semiconductor p-n junction diodes. Reading: Kasap ,

MTLE-6120: Advanced Electronic Properties of Materials. Semiconductor p-n junction diodes. Reading: Kasap , MTLE-6120: Advanced Electronic Properties of Materials 1 Semiconductor p-n junction diodes Reading: Kasap 6.1-6.5, 6.9-6.12 Metal-semiconductor contact potential 2 p-type n-type p-type n-type Same semiconductor

More information

p-n junction biasing, p-n I-V characteristics, p-n currents Norlaili Mohd. Noh EEE /09

p-n junction biasing, p-n I-V characteristics, p-n currents Norlaili Mohd. Noh EEE /09 CLASS 6&7 p-n junction biasing, p-n I-V characteristics, p-n currents 1 p-n junction biasing Unbiased p-n junction: the potential barrier is 0.7 V for Si and 0.3 V for Ge. Nett current across the p-n junction

More information

EE 6313 Homework Assignments

EE 6313 Homework Assignments EE 6313 Homework Assignments 1. Homework I: Chapter 1: 1.2, 1.5, 1.7, 1.10, 1.12 [Lattice constant only] (Due Sept. 1, 2009). 2. Homework II: Chapter 1, 2: 1.17, 2.1 (a, c) (k = π/a at zone edge), 2.3

More information

Lecture 8. Equations of State, Equilibrium and Einstein Relationships and Generation/Recombination

Lecture 8. Equations of State, Equilibrium and Einstein Relationships and Generation/Recombination Lecture 8 Equations of State, Equilibrium and Einstein Relationships and Generation/Recombination Reading: (Cont d) Notes and Anderson 2 sections 3.4-3.11 Energy Equilibrium Concept Consider a non-uniformly

More information

Chemistry Instrumental Analysis Lecture 8. Chem 4631

Chemistry Instrumental Analysis Lecture 8. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 8 UV to IR Components of Optical Basic components of spectroscopic instruments: stable source of radiant energy transparent container to hold sample device

More information

Purpose: To convert the received optical signal into an electrical lsignal.

Purpose: To convert the received optical signal into an electrical lsignal. OPTICAL DETECTORS Optical Detectors Purpose: To convert the received optical signal into an electrical lsignal. Requirements For Detector HIGH SENSITIVITY (at operating wave lengths) at normal op. temp

More information

Schottky Rectifiers Zheng Yang (ERF 3017,

Schottky Rectifiers Zheng Yang (ERF 3017, ECE442 Power Semiconductor Devices and Integrated Circuits Schottky Rectifiers Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Power Schottky Rectifier Structure 2 Metal-Semiconductor Contact The work function

More information

Photodiodes and other semiconductor devices

Photodiodes and other semiconductor devices Photodiodes and other semiconductor devices Chem 243 Winter 2017 What is a semiconductor? no e - Empty e levels Conduction Band a few e - Empty e levels Filled e levels Filled e levels lots of e - Empty

More information

Session 6: Solid State Physics. Diode

Session 6: Solid State Physics. Diode Session 6: Solid State Physics Diode 1 Outline A B C D E F G H I J 2 Definitions / Assumptions Homojunction: the junction is between two regions of the same material Heterojunction: the junction is between

More information

ENERGY BANDS AND GAPS IN SEMICONDUCTOR. Muhammad Hafeez Javed

ENERGY BANDS AND GAPS IN SEMICONDUCTOR. Muhammad Hafeez Javed ENERGY BANDS AND GAPS IN SEMICONDUCTOR Muhammad Hafeez Javed www.rmhjaved.com rmhjaved@gmail.com Out Line Introduction Energy band Classification of materials Direct and indirect band gap of SC Classification

More information

Chapter 1 Overview of Semiconductor Materials and Physics

Chapter 1 Overview of Semiconductor Materials and Physics Chapter 1 Overview of Semiconductor Materials and Physics Professor Paul K. Chu Conductivity / Resistivity of Insulators, Semiconductors, and Conductors Semiconductor Elements Period II III IV V VI 2 B

More information

8 Photo detectors. 8.1 Detector characteristics Responsivity R

8 Photo detectors. 8.1 Detector characteristics Responsivity R A photo detector is a device that converts the incident optical energy in a measurable signal, e.g., a voltage signal or an electric current. Photo detectors can be subdivided into two main classes: Photon

More information

Session 5: Solid State Physics. Charge Mobility Drift Diffusion Recombination-Generation

Session 5: Solid State Physics. Charge Mobility Drift Diffusion Recombination-Generation Session 5: Solid State Physics Charge Mobility Drift Diffusion Recombination-Generation 1 Outline A B C D E F G H I J 2 Mobile Charge Carriers in Semiconductors Three primary types of carrier action occur

More information

3.1 Introduction to Semiconductors. Y. Baghzouz ECE Department UNLV

3.1 Introduction to Semiconductors. Y. Baghzouz ECE Department UNLV 3.1 Introduction to Semiconductors Y. Baghzouz ECE Department UNLV Introduction In this lecture, we will cover the basic aspects of semiconductor materials, and the physical mechanisms which are at the

More information

EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors

EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors EE 5344 Introduction to MEMS CHAPTER 5 Radiation Sensors 5. Radiation Microsensors Radiation µ-sensors convert incident radiant signals into standard electrical out put signals. Radiant Signals Classification

More information

- A free electron in CB "meets" a hole in VB: the excess energy -> a photon energy.

- A free electron in CB meets a hole in VB: the excess energy -> a photon energy. 5.4. Recombination and Minority Carrier Injection 5.4.1 Direct and Indirect Recombination A free electron in CB "meets" a hole in VB: the excess energy > a photon energy. Energy CB ψ cb (k cb ) ψ vb (k

More information

Classification of Solids

Classification of Solids Classification of Solids Classification by conductivity, which is related to the band structure: (Filled bands are shown dark; D(E) = Density of states) Class Electron Density Density of States D(E) Examples

More information

Sample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013

Sample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013 Sample Exam # 2 ECEN 3320 Fall 203 Semiconductor Devices October 28, 203 Due November 4, 203. Below is the capacitance-voltage curve measured from a Schottky contact made on GaAs at T 300 K. Figure : Capacitance

More information

Lecture 2. Semiconductor Physics. Sunday 4/10/2015 Semiconductor Physics 1-1

Lecture 2. Semiconductor Physics. Sunday 4/10/2015 Semiconductor Physics 1-1 Lecture 2 Semiconductor Physics Sunday 4/10/2015 Semiconductor Physics 1-1 Outline Intrinsic bond model: electrons and holes Charge carrier generation and recombination Intrinsic semiconductor Doping:

More information

Supporting Information. InGaAs Nanomembrane/Si van der Waals Heterojunction. Photodiodes with Broadband and High Photoresponsivity

Supporting Information. InGaAs Nanomembrane/Si van der Waals Heterojunction. Photodiodes with Broadband and High Photoresponsivity Supporting Information InGaAs Nanomembrane/Si van der Waals Heterojunction Photodiodes with Broadband and High Photoresponsivity Doo-Seung Um, Youngsu Lee, Seongdong Lim, Jonghwa Park, Wen-Chun Yen, Yu-Lun

More information

Semiconductor Physics fall 2012 problems

Semiconductor Physics fall 2012 problems Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each

More information

Carriers Concentration and Current in Semiconductors

Carriers Concentration and Current in Semiconductors Carriers Concentration and Current in Semiconductors Carrier Transport Two driving forces for carrier transport: electric field and spatial variation of the carrier concentration. Both driving forces lead

More information

Basic cell design. Si cell

Basic cell design. Si cell Basic cell design Si cell 1 Concepts needed to describe photovoltaic device 1. energy bands in semiconductors: from bonds to bands 2. free carriers: holes and electrons, doping 3. electron and hole current:

More information

Spring Semester 2012 Final Exam

Spring Semester 2012 Final Exam Spring Semester 2012 Final Exam Note: Show your work, underline results, and always show units. Official exam time: 2.0 hours; an extension of at least 1.0 hour will be granted to anyone. Materials parameters

More information

Semiconductor-Detectors

Semiconductor-Detectors Semiconductor-Detectors 1 Motivation ~ 195: Discovery that pn-- junctions can be used to detect particles. Semiconductor detectors used for energy measurements ( Germanium) Since ~ 3 years: Semiconductor

More information

ELEC 4700 Assignment #2

ELEC 4700 Assignment #2 ELEC 4700 Assignment #2 Question 1 (Kasop 4.2) Molecular Orbitals and Atomic Orbitals Consider a linear chain of four identical atoms representing a hypothetical molecule. Suppose that each atomic wavefunction

More information

electronics fundamentals

electronics fundamentals electronics fundamentals circuits, devices, and applications THOMAS L. FLOYD DAVID M. BUCHLA Lesson 1: Diodes and Applications Semiconductors Figure 1-1 The Bohr model of an atom showing electrons in orbits

More information

Semiconductor Detectors

Semiconductor Detectors Semiconductor Detectors Summary of Last Lecture Band structure in Solids: Conduction band Conduction band thermal conductivity: E g > 5 ev Valence band Insulator Charge carrier in conductor: e - Charge

More information

SEMICONDUCTOR PHYSICS REVIEW BONDS,

SEMICONDUCTOR PHYSICS REVIEW BONDS, SEMICONDUCTOR PHYSICS REVIEW BONDS, BANDS, EFFECTIVE MASS, DRIFT, DIFFUSION, GENERATION, RECOMBINATION February 3, 2011 The University of Toledo, Department of Physics and Astronomy SSARE, PVIC Principles

More information

Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors

Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Literature Glen F. Knoll, Radiation

More information

Peak Electric Field. Junction breakdown occurs when the peak electric field in the PN junction reaches a critical value. For the N + P junction,

Peak Electric Field. Junction breakdown occurs when the peak electric field in the PN junction reaches a critical value. For the N + P junction, Peak Electric Field Junction breakdown occurs when the peak electric field in the P junction reaches a critical value. For the + P junction, qa E ( x) ( xp x), s W dep 2 s ( bi Vr ) 2 s potential barrier

More information

Semiconductor Device Physics

Semiconductor Device Physics 1 Semiconductor Device Physics Lecture 3 http://zitompul.wordpress.com 2 0 1 3 Semiconductor Device Physics 2 Three primary types of carrier action occur inside a semiconductor: Drift: charged particle

More information

Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes

Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes Problem 1: Semiconductor Fundamentals [30 points] A uniformly doped silicon sample of length 100µm and cross-sectional area 100µm 2

More information

Schottky Diodes (M-S Contacts)

Schottky Diodes (M-S Contacts) Schottky Diodes (M-S Contacts) Three MITs of the Day Band diagrams for ohmic and rectifying Schottky contacts Similarity to and difference from bipolar junctions on electrostatic and IV characteristics.

More information

Advantages / Disadvantages of semiconductor detectors

Advantages / Disadvantages of semiconductor detectors Advantages / Disadvantages of semiconductor detectors Semiconductor detectors have a high density (compared to gas detector) large energy loss in a short distance diffusion effect is smaller than in gas

More information

Conductivity and Semi-Conductors

Conductivity and Semi-Conductors Conductivity and Semi-Conductors J = current density = I/A E = Electric field intensity = V/l where l is the distance between two points Metals: Semiconductors: Many Polymers and Glasses 1 Electrical Conduction

More information

The pn junction. [Fonstad, Ghione]

The pn junction. [Fonstad, Ghione] The pn junction [Fonstad, Ghione] Band diagram On the vertical axis: potential energy of the electrons On the horizontal axis: now there is nothing: later we ll put the position qf s : work function (F

More information

Lecture 15: Optoelectronic devices: Introduction

Lecture 15: Optoelectronic devices: Introduction Lecture 15: Optoelectronic devices: Introduction Contents 1 Optical absorption 1 1.1 Absorption coefficient....................... 2 2 Optical recombination 5 3 Recombination and carrier lifetime 6 3.1

More information

EECS130 Integrated Circuit Devices

EECS130 Integrated Circuit Devices EECS130 Integrated Circuit Devices Professor Ali Javey 8/30/2007 Semiconductor Fundamentals Lecture 2 Read: Chapters 1 and 2 Last Lecture: Energy Band Diagram Conduction band E c E g Band gap E v Valence

More information

For the following statements, mark ( ) for true statement and (X) for wrong statement and correct it.

For the following statements, mark ( ) for true statement and (X) for wrong statement and correct it. Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year communications. Answer all the following questions Illustrate your answers with sketches when necessary. The

More information

Solid State Electronics. Final Examination

Solid State Electronics. Final Examination The University of Toledo EECS:4400/5400/7400 Solid State Electronic Section elssf08fs.fm - 1 Solid State Electronics Final Examination Problems Points 1. 1. 14 3. 14 Total 40 Was the exam fair? yes no

More information

Semiconductor Physics. Lecture 3

Semiconductor Physics. Lecture 3 Semiconductor Physics Lecture 3 Intrinsic carrier density Intrinsic carrier density Law of mass action Valid also if we add an impurity which either donates extra electrons or holes the number of carriers

More information

PHOTODETECTORS AND SILICON PHOTO MULTIPLIER

PHOTODETECTORS AND SILICON PHOTO MULTIPLIER ESE seminar Photodetectors - Sipm, P. Jarron - F. Powolny 1 PHOTODETECTORS AND SILICON PHOTO MULTIPLIER ESE seminar Pierre Jarron, Francois Powolny OUTLINE 2 Brief history and overview of photodetectors

More information

Semiconductor device structures are traditionally divided into homojunction devices

Semiconductor device structures are traditionally divided into homojunction devices 0. Introduction: Semiconductor device structures are traditionally divided into homojunction devices (devices consisting of only one type of semiconductor material) and heterojunction devices (consisting

More information

Structural Optimization of Silicon Carbide PIN Avalanche Photodiodes for UV Detection

Structural Optimization of Silicon Carbide PIN Avalanche Photodiodes for UV Detection Journal of the Korean Physical Society, Vol. 56, No. 2, February 2010, pp. 672 676 Structural Optimization of Silicon Carbide PIN Avalanche Photodiodes for UV Detection Ho-Young Cha School of Electronic

More information

Chap. 11 Semiconductor Diodes

Chap. 11 Semiconductor Diodes Chap. 11 Semiconductor Diodes Semiconductor diodes provide the best resolution for energy measurements, silicon based devices are generally used for charged-particles, germanium for photons. Scintillators

More information

Semiconductor Physical Electronics

Semiconductor Physical Electronics Semiconductor Physical Electronics Sheng S. Li Department of Electrical Engineering University of Florida Gainesville, Florida Plenum Press New York and London Contents CHAPTER 1. Classification of Solids

More information

Lecture 18. New gas detectors Solid state trackers

Lecture 18. New gas detectors Solid state trackers Lecture 18 New gas detectors Solid state trackers Time projection Chamber Full 3-D track reconstruction x-y from wires and segmented cathode of MWPC z from drift time de/dx information (extra) Drift over

More information

Theory of Electrical Characterization of Semiconductors

Theory of Electrical Characterization of Semiconductors Theory of Electrical Characterization of Semiconductors P. Stallinga Universidade do Algarve U.C.E.H. A.D.E.E.C. OptoElectronics SELOA Summer School May 2000, Bologna (It) Overview Devices: bulk Schottky

More information

UNIT I: Electronic Materials.

UNIT I: Electronic Materials. SIDDHARTH INSTITUTE OF ENGINEERING & TECHNOLOGY :: PUTTUR Siddharth Nagar, Narayanavanam Road 517583 QUESTION BANK (DESCRIPTIVE) Subject with Code: SEMICONDUCTOR PHYSICS (18HS0851) Course & Branch: B.Tech

More information

Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors

Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Literature Glen F. Knoll, Radiation

More information

Performance Analysis of an InGaAs Based p-i-n Photodetector

Performance Analysis of an InGaAs Based p-i-n Photodetector Performance Analysis of an InGaAs Based p-i-n Photodetector Diponkar Kundu 1, Dilip Kumar Sarker 2, Md. Galib Hasan 3, Pallab Kanti Podder 4, Md. Masudur Rahman 5 Abstract an InGaAs based p-i-n photodetector

More information

3.1 Absorption and Transparency

3.1 Absorption and Transparency 3.1 Absorption and Transparency 3.1.1 Optical Devices (definitions) 3.1.2 Photon and Semiconductor Interactions 3.1.3 Photon Intensity 3.1.4 Absorption 3.1 Absorption and Transparency Objective 1: Recall

More information

Chapter 7. The pn Junction

Chapter 7. The pn Junction Chapter 7 The pn Junction Chapter 7 PN Junction PN junction can be fabricated by implanting or diffusing donors into a P-type substrate such that a layer of semiconductor is converted into N type. Converting

More information

PN Junction

PN Junction P Junction 2017-05-04 Definition Power Electronics = semiconductor switches are used Analogue amplifier = high power loss 250 200 u x 150 100 u Udc i 50 0 0 50 100 150 200 250 300 350 400 i,u dc i,u u

More information

Semiconductor Physics Problems 2015

Semiconductor Physics Problems 2015 Semiconductor Physics Problems 2015 Page and figure numbers refer to Semiconductor Devices Physics and Technology, 3rd edition, by SM Sze and M-K Lee 1. The purest semiconductor crystals it is possible

More information

Carriers Concentration, Current & Hall Effect in Semiconductors. Prof.P. Ravindran, Department of Physics, Central University of Tamil Nadu, India

Carriers Concentration, Current & Hall Effect in Semiconductors. Prof.P. Ravindran, Department of Physics, Central University of Tamil Nadu, India Carriers Concentration, Current & Hall Effect in Semiconductors 1 Prof.P. Ravindran, Department of Physics, Central University of Tamil Nadu, India http://folk.uio.no/ravi/semi2013 Conductivity Charge

More information

Chapter 7. Solar Cell

Chapter 7. Solar Cell Chapter 7 Solar Cell 7.0 Introduction Solar cells are useful for both space and terrestrial application. Solar cells furnish the long duration power supply for satellites. It converts sunlight directly

More information

pn JUNCTION THE SHOCKLEY MODEL

pn JUNCTION THE SHOCKLEY MODEL The pn Junction: The Shockley Model ( S. O. Kasap, 1990-001) 1 pn JUNCTION THE SHOCKLEY MODEL Safa Kasap Department of Electrical Engineering University of Saskatchewan Canada Although the hole and its

More information

Introduction to Semiconductor Integrated Optics

Introduction to Semiconductor Integrated Optics Introduction to Semiconductor Integrated Optics Hans P. Zappe Artech House Boston London Contents acknowledgments reface itroduction Chapter 1 Basic Electromagnetics 1 1.1 General Relationships 1 1.1.1

More information

Effective masses in semiconductors

Effective masses in semiconductors Effective masses in semiconductors The effective mass is defined as: In a solid, the electron (hole) effective mass represents how electrons move in an applied field. The effective mass reflects the inverse

More information

B12: Semiconductor Devices

B12: Semiconductor Devices B12: Semiconductor Devices Example Sheet 2: Solutions Question 1 To get from eq. (5.70) of the notes to the expression given in the examples sheet, we simply invoke the relations n 0 p 0, n 0 n 0. In this

More information

collisions of electrons. In semiconductor, in certain temperature ranges the conductivity increases rapidly by increasing temperature

collisions of electrons. In semiconductor, in certain temperature ranges the conductivity increases rapidly by increasing temperature 1.9. Temperature Dependence of Semiconductor Conductivity Such dependence is one most important in semiconductor. In metals, Conductivity decreases by increasing temperature due to greater frequency of

More information

Avalanche breakdown. Impact ionization causes an avalanche of current. Occurs at low doping

Avalanche breakdown. Impact ionization causes an avalanche of current. Occurs at low doping Avalanche breakdown Impact ionization causes an avalanche of current Occurs at low doping Zener tunneling Electrons tunnel from valence band to conduction band Occurs at high doping Tunneling wave decays

More information

COURSE OUTLINE. Introduction Signals and Noise Filtering Sensors: PD5 Avalanche PhotoDiodes. Sensors, Signals and Noise 1

COURSE OUTLINE. Introduction Signals and Noise Filtering Sensors: PD5 Avalanche PhotoDiodes. Sensors, Signals and Noise 1 Sensors, Signals and Noise 1 COURSE OUTLINE Introduction Signals and Noise Filtering Sensors: PD5 Avalanche PhotoDiodes Avalanche Photo-Diodes (APD) 2 Impact ionization in semiconductors Linear amplification

More information

Solid State Physics SEMICONDUCTORS - IV. Lecture 25. A.H. Harker. Physics and Astronomy UCL

Solid State Physics SEMICONDUCTORS - IV. Lecture 25. A.H. Harker. Physics and Astronomy UCL Solid State Physics SEMICONDUCTORS - IV Lecture 25 A.H. Harker Physics and Astronomy UCL 9.9 Carrier diffusion and recombination Suppose we have a p-type semiconductor, i.e. n h >> n e. (1) Create a local

More information

Current mechanisms Exam January 27, 2012

Current mechanisms Exam January 27, 2012 Current mechanisms Exam January 27, 2012 There are four mechanisms that typically cause currents to flow: thermionic emission, diffusion, drift, and tunneling. Explain briefly which kind of current mechanisms

More information

PHOTOVOLTAICS Fundamentals

PHOTOVOLTAICS Fundamentals PHOTOVOLTAICS Fundamentals PV FUNDAMENTALS Semiconductor basics pn junction Solar cell operation Design of silicon solar cell SEMICONDUCTOR BASICS Allowed energy bands Valence and conduction band Fermi

More information

EE 446/646 Photovoltaic Devices I. Y. Baghzouz

EE 446/646 Photovoltaic Devices I. Y. Baghzouz EE 446/646 Photovoltaic Devices I Y. Baghzouz What is Photovoltaics? First used in about 1890, the word has two parts: photo, derived from the Greek word for light, volt, relating to electricity pioneer

More information

SEMICONDUCTOR PHYSICS

SEMICONDUCTOR PHYSICS SEMICONDUCTOR PHYSICS by Dibyendu Chowdhury Semiconductors The materials whose electrical conductivity lies between those of conductors and insulators, are known as semiconductors. Silicon Germanium Cadmium

More information

8. Schottky contacts / JFETs

8. Schottky contacts / JFETs Technische Universität Graz Institute of Solid State Physics 8. Schottky contacts / JFETs Nov. 21, 2018 Technische Universität Graz Institute of Solid State Physics metal - semiconductor contacts Photoelectric

More information

Misan University College of Engineering Electrical Engineering Department. Exam: Final semester Date: 17/6/2017

Misan University College of Engineering Electrical Engineering Department. Exam: Final semester Date: 17/6/2017 Misan University College of Engineering Electrical Engineering Department Subject: Electronic I Class: 1 st stage Exam: Final semester Date: 17/6/2017 Examiner: Dr. Baqer. O. TH. Time: 3 hr. Note: Answer

More information

MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University

MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University Practice Final Exam 1 Read the questions carefully Label all figures

More information

Chapter 17. λ 2 = 1.24 = 6200 Å. λ 2 cutoff at too short a wavelength λ 1 cutoff at to long a wavelength (increases bandwidth for noise reduces S/N).

Chapter 17. λ 2 = 1.24 = 6200 Å. λ 2 cutoff at too short a wavelength λ 1 cutoff at to long a wavelength (increases bandwidth for noise reduces S/N). 70 Chapter 17 17.1 We wish to use a photodiode as a detector for a signal of 9000 Å wavelength. Which would be the best choice of material for the photodiode, a semiconductor of bandgap = 0.5 ev, bandgap

More information

ELECTRONIC DEVICES AND CIRCUITS SUMMARY

ELECTRONIC DEVICES AND CIRCUITS SUMMARY ELECTRONIC DEVICES AND CIRCUITS SUMMARY Classification of Materials: Insulator: An insulator is a material that offers a very low level (or negligible) of conductivity when voltage is applied. Eg: Paper,

More information

Direct and Indirect Semiconductor

Direct and Indirect Semiconductor Direct and Indirect Semiconductor Allowed values of energy can be plotted vs. the propagation constant, k. Since the periodicity of most lattices is different in various direction, the E-k diagram must

More information

Unit IV Semiconductors Engineering Physics

Unit IV Semiconductors Engineering Physics Introduction A semiconductor is a material that has a resistivity lies between that of a conductor and an insulator. The conductivity of a semiconductor material can be varied under an external electrical

More information

Tunneling transport. Courtesy Prof. S. Sawyer, RPI Also Davies Ch. 5

Tunneling transport. Courtesy Prof. S. Sawyer, RPI Also Davies Ch. 5 unneling transport Courtesy Prof. S. Sawyer, RPI Also Davies Ch. 5 Electron transport properties l e : electronic mean free path l φ : phase coherence length λ F : Fermi wavelength ecture Outline Important

More information

n N D n p = n i p N A

n N D n p = n i p N A Summary of electron and hole concentration in semiconductors Intrinsic semiconductor: E G n kt i = pi = N e 2 0 Donor-doped semiconductor: n N D where N D is the concentration of donor impurity Acceptor-doped

More information

Schottky diodes. JFETs - MESFETs - MODFETs

Schottky diodes. JFETs - MESFETs - MODFETs Technische Universität Graz Institute of Solid State Physics Schottky diodes JFETs - MESFETs - MODFETs Quasi Fermi level When the charge carriers are not in equilibrium the Fermi energy can be different

More information

Astronomical Observing Techniques 2017 Lecture 9: Silicon Eyes 1

Astronomical Observing Techniques 2017 Lecture 9: Silicon Eyes 1 Astronomical Observing Techniques 2017 Lecture 9: Silicon Eyes 1 Christoph U. Keller keller@strw.leidenuniv.nl Content 1. Detector Types 2. Crystal La>ces 3. Electronic Bands 4. Fermi Energy and Fermi

More information

PHYS208 P-N Junction. Olav Torheim. May 30, 2007

PHYS208 P-N Junction. Olav Torheim. May 30, 2007 1 PHYS208 P-N Junction Olav Torheim May 30, 2007 1 Intrinsic semiconductors The lower end of the conduction band is a parabola, just like in the quadratic free electron case (E = h2 k 2 2m ). The density

More information

Temperature and Silicon Film Thickness Influence on the Operation of Lateral SOI PIN Photodiodes for Detection of Short Wavelengths

Temperature and Silicon Film Thickness Influence on the Operation of Lateral SOI PIN Photodiodes for Detection of Short Wavelengths 04 (51)-AF:Modelo-AF 8/20/11 6:37 AM Page 107 Temperature and Silicon Film Thickness Influence on the Operation of Lateral SOI PIN Photodiodes for Detection of Short Wavelengths Michelly de Souza 1, Olivier

More information

Chapter 1 Semiconductor basics

Chapter 1 Semiconductor basics Chapter 1 Semiconductor basics ELEC-H402/CH1: Semiconductor basics 1 Basic semiconductor concepts Semiconductor basics Semiconductors, silicon and hole-electron pair Intrinsic silicon properties Doped

More information

Basic Physics of Semiconductors

Basic Physics of Semiconductors Basic Physics of Semiconductors Semiconductor materials and their properties PN-junction diodes Reverse Breakdown EEM 205 Electronics I Dicle University, EEE Dr. Mehmet Siraç ÖZERDEM Semiconductor Physics

More information