Light absorption in solid matter: First experiment on external photoelectric effect
|
|
- Margaret Fitzgerald
- 7 years ago
- Views:
Transcription
1 Light absorption in solid matter: First experiment on external photoelectric effect Photoelectric cell (~1890) In photoelectric cell, electrons are liberated from the surface of a metallic conductor (cathode) by absorbing energy from light shining on the metal's surface. Free electrons drift to anode and form the current through the cell. The number of electrons released from the metal can be determined by measuring the current. The kinetic energy of electrons could be measured by the force needed to stop them (the charge applied to the metal) As the light shining on a metal becomes increasingly intense, the classical wave (electromagnetic) theory of light suggests that the electrons that absorb the light will be liberated from the metal with more and more energy.
2 In 1902, Phillip Lenard studied the photoelectric effect and discovered a number of key features: 1. The greater the intensity of the incoming light, the greater the number of electrons that were released. After all, when bigger, more powerful waves start hitting an ocean beach, they dislodge more sand than smaller, weaker waves. That observation made sense. 2. Next discovery did not make sense at all in the world of classical physics. He discovered that the kinetic energy contained in each of the escaping electrons did not increase when the intensity of the light increased. Where did the extra energy go? No answer. 3. Next discovery did not make sense at all in the world of classical physics. While increasing the intensity of light didn t increase the energy of the released electrons, increasing the frequency of light (light color) did. Weaker waves with higher frequency supplied more energy to electrons than stronger waves with lower frequency. 4. Next discovery did not make sense at all in the world of classical physics. Light with low enough frequency could not release electrons from the metal no matter how strong it was. The photo-effect occurred only if the light frequency was above certain threshold value.
3 Quantum nature of light Albert Einstein ( ), probably the best-known scientist of the twentieth century, did not talk until he was three. However, even as a youth, he showed great mathematical ability. Einstein dropped out of school for a year when he was fifteen. He eventually attended the Swiss Federal Institute of Technology, but often cut classes; he passed by studying a classmate's notes. His professors refused to recommend him for an academic position which is why he was working in the patent office in Bern, Switzerland, in 1905.
4 Quantum nature of light In 1905, Einstein published a theory of the photoelectric effect. He believed that light and other forms of radiations are made up of discrete bundles of energy (particles, or quasi-particles), and that the energy of each bundle depends on the light s frequency. This idea was soon supported by Max Planck s theory, stating that the energy E of a single particle of light (photon) is given by: E = h ν, where h is a Plank constant and ν is the light frequency. In 1921, Albert Einstein received the Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."
5 Absorption Related electrical process: electron - hole pair generation The photon with the energy exceeding the bandgap energy of semiconductor can be absorbed. The photon disappears; the photon energy excites the electron from the valence band into the conduction band. As a result, one e-h pair is being created Photon absorption E = h ν = Ε g
6 Radiation Related electrical process: electron - hole pair recombination When the excited electron meets the hole in the valence band, it may occupy that place. As a result the e-h pair disappear; this process is called recombination. During recombination, the electron energy is released as a photon with the energy closed to the bandgap energy of the semiconductor. Photon Photon absorption emission E = h ν = Ε h ν = Ε g g
7 Photon energy wavelength relation c E ph = h ν = h λ Here h = J s; v = m/s; Substituting the constants into the equation for E ph, we get: Ε PH [ ev ] = λ[ µ m] Here, we have used: 1 ev = J; 1 µm = 10-6 m Example: find the energy of the photon corresponding to the light wavelength of λ = 0.63 µm (RED LIGHT) Substituting the value of λ into the above expression for the photon energy, we find: E ph 1.97 ev;
8 Photon energies, wavelengths and semiconductor bandgaps
9 E ph 1.97 ev; What semiconductor material can absorb and emit the photon of such energy?
10 Example problem The beam of red photons (λ=0.63 µm) creates an optical power density of 1 W/cm 3 in a GaAs sample). The electron-hole life time is GaAs 5 µs. Find the concentration of photo generated electron-hole pairs Solution Optical power density = Photon energy Number of photons per second per unit volume: Note: Number of photons per second per unit volume absorbed in the material, is the generation rate G P opt = E ph G; G = P opt /E ph ;E ph = 1.97 ev; G = (1W/cm -3 ) /(1.97*1.6e-19)J = 3.17 x cm -3 s -1. G = R = n/τ; n= G x τ; n = 3.17 x cm -3 s -1 x 5x10-6 s = 1.58x10 13 cm -3
11 The energy and momentum conservation laws require certain conditions to be satisfied to make this absorption possible. -- Electron Photon Hole For the direct photon into e-h pair transformation, E ph = E g ; p ph = p e -p h, where E ph = h v is the photon energy, p is the momentum of the photon, of the electron or of the hole.
12 The energy and momentum conservation laws require certain conditions to be satisfied to make this absorption possible. E ph = E g ; p ph = p e -p h, The mass of the photon is negligibly small: p ph 0; (because p = m v) Therefore after the absorption the e and the h must have equal momentums: p e p h ;
13 The momentum of the quantum-mechanical particle of the mass m and velocity v is given by 2π λ p = m v = k where k = is the wave vector of the particle. Band diagram of direct-band semiconductor material and absorption/emission processes in such material: 1 absorption 2 - emission
14 Comments. A simple way to understand the semiconductor band diagram in energy k coordinates is as follows. The kinetic energy of a free particle using a classic mechanics approach is k E = 2 mv Since m v =, we expect that in quantum mechanical approximation, E = 2 2 k 2 m 2 i.e. the E(k) dependence in the simplest case of free or quasi-free particle must be parabolic. This indeed is the case for some semiconductors (as shown above for the materials like GaAs, InP, GaN etc.)
15 For other materials, for instance, Si, the dependence is more complicated: For the photon emission (top) or absorption (bottom), the THIRD particle IS NEEDED to meet the momentum conservation. This third particle is usually a PHONON (the crystal lattice vibration).
16 Donor - Acceptor and Impurity-band Absorption
17 Band donor (a) and acceptor - band (b) absorption Low-energy (a) donor-band and (b) acceptor-band absorption
18 Radiation in semiconductors In general, the reverse of all the absorption processes considered above can occur to produce radiation. 1) Band - to -band recombination (radiation) 2) Donor- acceptor recombination 3) Impurity band recombination.
19 Not ANY recombination produces the RADIATION In case of indirect bands, the recombination produces phonons rather than photons. This is particularly the case of the most important semiconductor material, Si.
20 Log-scale Absorption spectra
PHOTOELECTRIC EFFECT AND DUAL NATURE OF MATTER AND RADIATIONS
PHOTOELECTRIC EFFECT AND DUAL NATURE OF MATTER AND RADIATIONS 1. Photons 2. Photoelectric Effect 3. Experimental Set-up to study Photoelectric Effect 4. Effect of Intensity, Frequency, Potential on P.E.
More informationTHE CURRENT-VOLTAGE CHARACTERISTICS OF AN LED AND A MEASUREMENT OF PLANCK S CONSTANT Physics 258/259
DSH 2004 THE CURRENT-VOLTAGE CHARACTERISTICS OF AN LED AND A MEASUREMENT OF PLANCK S CONSTANT Physics 258/259 I. INTRODUCTION Max Planck (1858-1947) was an early pioneer in the field of quantum physics.
More informationName Date Class ELECTRONS IN ATOMS. Standard Curriculum Core content Extension topics
13 ELECTRONS IN ATOMS Conceptual Curriculum Concrete concepts More abstract concepts or math/problem-solving Standard Curriculum Core content Extension topics Honors Curriculum Core honors content Options
More informationEnergy band diagrams. Single atom. Crystal. Excited electrons cannot move. Excited electrons can move (free electrons)
Energy band diagrams In the atoms, the larger the radius, the higher the electron potential energy Hence, electron position can be described either by radius or by its potential energy In the semiconductor
More informationUniversity of California at Santa Cruz Electrical Engineering Department EE-145L: Properties of Materials Laboratory
University of California at Santa Cruz Electrical Engineering Department EE-145L: Properties of Materials Laboratory Lab 8: Optical Absorption Spring 2002 Yan Zhang and Ali Shakouri, 05/22/2002 (Based
More informationSolid State Detectors = Semi-Conductor based Detectors
Solid State Detectors = Semi-Conductor based Detectors Materials and their properties Energy bands and electronic structure Charge transport and conductivity Boundaries: the p-n junction Charge collection
More informationHow To Understand Light And Color
PRACTICE EXAM IV P202 SPRING 2004 1. In two separate double slit experiments, an interference pattern is observed on a screen. In the first experiment, violet light (λ = 754 nm) is used and a second-order
More informationDoes Quantum Mechanics Make Sense? Size
Does Quantum Mechanics Make Sense? Some relatively simple concepts show why the answer is yes. Size Classical Mechanics Quantum Mechanics Relative Absolute What does relative vs. absolute size mean? Why
More informationFYS3410 - Vår 2015 (Kondenserte fasers fysikk) http://www.uio.no/studier/emner/matnat/fys/fys3410/v15/index.html
FYS3410 - Vår 015 (Kondenserte fasers fysikk) http://www.uio.no/studier/emner/matnat/fys/fys3410/v15/index.html Pensum: Introduction to Solid State Physics by Charles Kittel (Chapters 1-9 and 17, 18, 0,
More informationAtomic Structure Ron Robertson
Atomic Structure Ron Robertson r2 n:\files\courses\1110-20\2010 possible slides for web\atomicstructuretrans.doc I. What is Light? Debate in 1600's: Since waves or particles can transfer energy, what is
More informationNanoelectronics. Chapter 2 Classical Particles, Classical Waves, and Quantum Particles. Q.Li@Physics.WHU@2015.3
Nanoelectronics Chapter 2 Classical Particles, Classical Waves, and Quantum Particles Q.Li@Physics.WHU@2015.3 1 Electron Double-Slit Experiment Q.Li@Physics.WHU@2015.3 2 2.1 Comparison of Classical and
More informationPhotons. ConcepTest 27.1. 1) red light 2) yellow light 3) green light 4) blue light 5) all have the same energy. Which has more energy, a photon of:
ConcepTest 27.1 Photons Which has more energy, a photon of: 1) red light 2) yellow light 3) green light 4) blue light 5) all have the same energy 400 nm 500 nm 600 nm 700 nm ConcepTest 27.1 Photons Which
More informationThe Physics of Energy sources Renewable sources of energy. Solar Energy
The Physics of Energy sources Renewable sources of energy Solar Energy B. Maffei Bruno.maffei@manchester.ac.uk Renewable sources 1 Solar power! There are basically two ways of using directly the radiative
More informationThe Phenomenon of Photoelectric Emission:
The Photoelectric Effect. The Wave particle duality of light Light, like any other E.M.R (electromagnetic radiation) has got a dual nature. That is there are experiments that prove that it is made up of
More informationWAVES AND ELECTROMAGNETIC RADIATION
WAVES AND ELECTROMAGNETIC RADIATION All waves are characterized by their wavelength, frequency and speed. Wavelength (lambda, ): the distance between any 2 successive crests or troughs. Frequency (nu,):
More informationWave Function, ψ. Chapter 28 Atomic Physics. The Heisenberg Uncertainty Principle. Line Spectrum
Wave Function, ψ Chapter 28 Atomic Physics The Hydrogen Atom The Bohr Model Electron Waves in the Atom The value of Ψ 2 for a particular object at a certain place and time is proportional to the probability
More informationExperiment #5: Qualitative Absorption Spectroscopy
Experiment #5: Qualitative Absorption Spectroscopy One of the most important areas in the field of analytical chemistry is that of spectroscopy. In general terms, spectroscopy deals with the interactions
More informationChapter 5. Second Edition ( 2001 McGraw-Hill) 5.6 Doped GaAs. Solution
Chapter 5 5.6 Doped GaAs Consider the GaAs crystal at 300 K. a. Calculate the intrinsic conductivity and resistivity. Second Edition ( 2001 McGraw-Hill) b. In a sample containing only 10 15 cm -3 ionized
More informationLesson 33: Photoelectric Effect
Lesson 33: Photoelectric Effect Hertz Experiment Heinrich Hertz was doing experiments in 1887 to test some of Maxwell's theories of EMR. One of the experiments involved using a coil of wire as a receiver
More informationChapter 18: The Structure of the Atom
Chapter 18: The Structure of the Atom 1. For most elements, an atom has A. no neutrons in the nucleus. B. more protons than electrons. C. less neutrons than electrons. D. just as many electrons as protons.
More informationSpectrophotometry and the Beer-Lambert Law: An Important Analytical Technique in Chemistry
Spectrophotometry and the Beer-Lambert Law: An Important Analytical Technique in Chemistry Jon H. Hardesty, PhD and Bassam Attili, PhD Collin College Department of Chemistry Introduction: In the last lab
More informationCrystalline solids. A solid crystal consists of different atoms arranged in a periodic structure.
Crystalline solids A solid crystal consists of different atoms arranged in a periodic structure. Crystals can be formed via various bonding mechanisms: Ionic bonding Covalent bonding Metallic bonding Van
More informationVacuum Evaporation Recap
Sputtering Vacuum Evaporation Recap Use high temperatures at high vacuum to evaporate (eject) atoms or molecules off a material surface. Use ballistic flow to transport them to a substrate and deposit.
More informationElectron spectroscopy Lecture 1-21. Kai M. Siegbahn (1918 - ) Nobel Price 1981 High resolution Electron Spectroscopy
Electron spectroscopy Lecture 1-21 Kai M. Siegbahn (1918 - ) Nobel Price 1981 High resolution Electron Spectroscopy 653: Electron Spectroscopy urse structure cture 1. Introduction to electron spectroscopies
More informationBroadband THz Generation from Photoconductive Antenna
Progress In Electromagnetics Research Symposium 2005, Hangzhou, China, August 22-26 331 Broadband THz Generation from Photoconductive Antenna Qing Chang 1, Dongxiao Yang 1,2, and Liang Wang 1 1 Zhejiang
More informationLecture 3: Optical Properties of Bulk and Nano. 5 nm
Lecture 3: Optical Properties of Bulk and Nano 5 nm The Previous Lecture Origin frequency dependence of χ in real materials Lorentz model (harmonic oscillator model) 0 e - n( ) n' n '' n ' = 1 + Nucleus
More informationChemistry 2 Chapter 13: Electrons in Atoms Please do not write on the test Use an answer sheet! 1 point/problem 45 points total
Chemistry 2 Chapter 13: Electrons in Atoms Please do not write on the test Use an answer sheet! 1 point/problem 45 points total 1. Calculate the energy in joules of a photon of red light that has a frequency
More information- particle with kinetic energy E strikes a barrier with height U 0 > E and width L. - classically the particle cannot overcome the barrier
Tunnel Effect: - particle with kinetic energy E strikes a barrier with height U 0 > E and width L - classically the particle cannot overcome the barrier - quantum mechanically the particle can penetrated
More informationSolid-State Physics: The Theory of Semiconductors (Ch. 10.6-10.8) SteveSekula, 30 March 2010 (created 29 March 2010)
Modern Physics (PHY 3305) Lecture Notes Modern Physics (PHY 3305) Lecture Notes Solid-State Physics: The Theory of Semiconductors (Ch. 10.6-10.8) SteveSekula, 30 March 2010 (created 29 March 2010) Review
More informationBoardworks AS Physics
Boardworks AS Physics Vectors 24 slides 11 Flash activities Prefixes, scalars and vectors Guide to the SI unit prefixes of orders of magnitude Matching powers of ten to their SI unit prefixes Guide to
More informationTypes of Epitaxy. Homoepitaxy. Heteroepitaxy
Epitaxy Epitaxial Growth Epitaxy means the growth of a single crystal film on top of a crystalline substrate. For most thin film applications (hard and soft coatings, optical coatings, protective coatings)
More information5. The Nature of Light. Does Light Travel Infinitely Fast? EMR Travels At Finite Speed. EMR: Electric & Magnetic Waves
5. The Nature of Light Light travels in vacuum at 3.0. 10 8 m/s Light is one form of electromagnetic radiation Continuous radiation: Based on temperature Wien s Law & the Stefan-Boltzmann Law Light has
More information13- What is the maximum number of electrons that can occupy the subshell 3d? a) 1 b) 3 c) 5 d) 2
Assignment 06 A 1- What is the energy in joules of an electron undergoing a transition from n = 3 to n = 5 in a Bohr hydrogen atom? a) -3.48 x 10-17 J b) 2.18 x 10-19 J c) 1.55 x 10-19 J d) -2.56 x 10-19
More information2 Absorbing Solar Energy
2 Absorbing Solar Energy 2.1 Air Mass and the Solar Spectrum Now that we have introduced the solar cell, it is time to introduce the source of the energy the sun. The sun has many properties that could
More informationChemistry 102 Summary June 24 th. Properties of Light
Chemistry 102 Summary June 24 th Properties of Light - Energy travels through space in the form of electromagnetic radiation (EMR). - Examples of types of EMR: radio waves, x-rays, microwaves, visible
More information- thus, the total number of atoms per second that absorb a photon is
Stimulated Emission of Radiation - stimulated emission is referring to the emission of radiation (a photon) from one quantum system at its transition frequency induced by the presence of other photons
More informationEnergy Transport. Focus on heat transfer. Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids)
Energy Transport Focus on heat transfer Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids) Conduction Conduction heat transfer occurs only when there is physical contact
More informationLecture 3: Optical Properties of Bulk and Nano. 5 nm
Lecture 3: Optical Properties of Bulk and Nano 5 nm First H/W#1 is due Sept. 10 Course Info The Previous Lecture Origin frequency dependence of χ in real materials Lorentz model (harmonic oscillator model)
More informationElectron Orbits. Binding Energy. centrifugal force: electrostatic force: stability criterion: kinetic energy of the electron on its orbit:
Electron Orbits In an atom model in which negatively charged electrons move around a small positively charged nucleus stable orbits are possible. Consider the simple example of an atom with a nucleus of
More informationBlackbody Radiation References INTRODUCTION
Blackbody Radiation References 1) R.A. Serway, R.J. Beichner: Physics for Scientists and Engineers with Modern Physics, 5 th Edition, Vol. 2, Ch.40, Saunders College Publishing (A Division of Harcourt
More informationMAKING SENSE OF ENERGY Electromagnetic Waves
Adapted from State of Delaware TOE Unit MAKING SENSE OF ENERGY Electromagnetic Waves GOALS: In this Part of the unit you will Learn about electromagnetic waves, how they are grouped, and how each group
More informationPhysics 30 Worksheet # 14: Michelson Experiment
Physics 30 Worksheet # 14: Michelson Experiment 1. The speed of light found by a Michelson experiment was found to be 2.90 x 10 8 m/s. If the two hills were 20.0 km apart, what was the frequency of the
More informationSearching New Materials for Energy Conversion and Energy Storage
Searching New Materials for Energy Conversion and Energy Storage ZÜRICH & COLLEGIU UM HELVE ETICUM R. NES SPER ETH 1. Renewable Energy 2. Solar Cells 3. Thermoelectricity 4. Fast High Energy Li-Ion Batteries
More informationArrangement of Electrons in Atoms
CHAPTER 4 PRE-TEST Arrangement of Electrons in Atoms In the space provided, write the letter of the term that best completes each sentence or best answers each question. 1. Which of the following orbital
More informationTIME OF COMPLETION NAME SOLUTION DEPARTMENT OF NATURAL SCIENCES. PHYS 3650, Exam 2 Section 1 Version 1 October 31, 2005 Total Weight: 100 points
TIME OF COMPLETION NAME SOLUTION DEPARTMENT OF NATURAL SCIENCES PHYS 3650, Exam 2 Section 1 Version 1 October 31, 2005 Total Weight: 100 points 1. Check your examination for completeness prior to starting.
More informationFUNDAMENTAL PROPERTIES OF SOLAR CELLS
FUNDAMENTAL PROPERTIES OF SOLAR CELLS January 31, 2012 The University of Toledo, Department of Physics and Astronomy SSARE, PVIC Principles and Varieties of Solar Energy (PHYS 4400) and Fundamentals of
More informationLight as a Wave. The Nature of Light. EM Radiation Spectrum. EM Radiation Spectrum. Electromagnetic Radiation
The Nature of Light Light and other forms of radiation carry information to us from distance astronomical objects Visible light is a subset of a huge spectrum of electromagnetic radiation Maxwell pioneered
More informationwhere h = 6.62 10-34 J s
Electromagnetic Spectrum: Refer to Figure 12.1 Molecular Spectroscopy: Absorption of electromagnetic radiation: The absorptions and emissions of electromagnetic radiation are related molecular-level phenomena
More informationHSC Physics Notes From Ideas to Implementation
HSC Physics Notes From Ideas to Implementation 9.3-1. Increased understanding of cathode rays led to the development of the television 1. explain why the apparent inconsistent behaviour of cathode rays
More informationFree Electron Fermi Gas (Kittel Ch. 6)
Free Electron Fermi Gas (Kittel Ch. 6) Role of Electrons in Solids Electrons are responsible for binding of crystals -- they are the glue that hold the nuclei together Types of binding (see next slide)
More informationG482 Electrons, Waves and Photons; Revision Notes Module 1: Electric Current
G482 Electrons, Waves and Photons; Revision Notes Module 1: Electric Current Electric Current A net flow of charged particles. Electrons in a metal Ions in an electrolyte Conventional Current A model used
More informationHomework #10 (749508)
Homework #10 (749508) Current Score: 0 out of 100 Description Homework on quantum physics and radioactivity Instructions Answer all the questions as best you can. 1. Hewitt10 32.E.001. [481697] 0/5 points
More informationPhotovoltaic and Photoelectrochemical Solar Cells
Photovoltaic and Photoelectrochemical Solar Cells EDDIE FOROUZAN, PH.D. ARTIN ENGINEERING AND CONSULTING GROUP, INC. 7933 SILVERTON AVE. #715 SAN DIEGO, CA 92128 PSES San Diego Chapter 2012-02-10 History
More informationQ1. The diagram below shows the range of wavelengths and frequencies for all the types of radiation in the electromagnetic spectrum.
Q. The diagram below shows the range of wavelengths and frequencies for all the types of radiation in the electromagnetic spectrum. X rays, which have frequencies in the range 0 8 0 2 Hz are already marked
More informationLight. What is light?
Light What is light? 1. How does light behave? 2. What produces light? 3. What type of light is emitted? 4. What information do you get from that light? Methods in Astronomy Photometry Measure total amount
More informationProject 2B Building a Solar Cell (2): Solar Cell Performance
April. 15, 2010 Due April. 29, 2010 Project 2B Building a Solar Cell (2): Solar Cell Performance Objective: In this project we are going to experimentally measure the I-V characteristics, energy conversion
More informationLecture 1: Basic Concepts on Absorption and Fluorescence
Lecture 1: Basic Concepts on Absorption and Fluorescence Nicholas G. James Cell and Molecular Biology University of Hawaii at Manoa, Honolulu The Goal The emission of light after absorption of an outside
More informationSolar Energy. Outline. Solar radiation. What is light?-- Electromagnetic Radiation. Light - Electromagnetic wave spectrum. Electromagnetic Radiation
Outline MAE 493R/593V- Renewable Energy Devices Solar Energy Electromagnetic wave Solar spectrum Solar global radiation Solar thermal energy Solar thermal collectors Solar thermal power plants Photovoltaics
More informationLevel 3 Achievement Scale
Unit 1: Atoms Level 3 Achievement Scale Can state the key results of the experiments associated with Dalton, Rutherford, Thomson, Chadwick, and Bohr and what this lead each to conclude. Can explain that
More informationReview of the isotope effect in the hydrogen spectrum
Review of the isotope effect in the hydrogen spectrum 1 Balmer and Rydberg Formulas By the middle of the 19th century it was well established that atoms emitted light at discrete wavelengths. This is in
More informationUNIT I: INTRFERENCE & DIFFRACTION Div. B Div. D Div. F INTRFERENCE
107002: EngineeringPhysics Teaching Scheme: Lectures: 4 Hrs/week Practicals-2 Hrs./week T.W.-25 marks Examination Scheme: Paper-50 marks (2 hrs) Online -50marks Prerequisite: Basics till 12 th Standard
More informationDO PHYSICS ONLINE FROM QUANTA TO QUARKS QUANTUM (WAVE) MECHANICS
DO PHYSICS ONLINE FROM QUANTA TO QUARKS QUANTUM (WAVE) MECHANICS Quantum Mechanics or wave mechanics is the best mathematical theory used today to describe and predict the behaviour of particles and waves.
More informationAtoms Absorb & Emit Light
Atoms Absorb & Emit Light Spectra The wavelength of the light that an element emits or absorbs is its fingerprint. Atoms emit and absorb light First Test is Thurs, Feb 1 st About 30 multiple choice questions
More informationMCQ - ENERGY and CLIMATE
1 MCQ - ENERGY and CLIMATE 1. The volume of a given mass of water at a temperature of T 1 is V 1. The volume increases to V 2 at temperature T 2. The coefficient of volume expansion of water may be calculated
More information"in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta". h is the Planck constant he called it
1 2 "in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta". h is the Planck constant he called it the quantum of action 3 Newton believed in the corpuscular
More information3. Diodes and Diode Circuits. 3. Diodes and Diode Circuits TLT-8016 Basic Analog Circuits 2005/2006 1
3. Diodes and Diode Circuits 3. Diodes and Diode Circuits TLT-8016 Basic Analog Circuits 2005/2006 1 3.1 Diode Characteristics Small-Signal Diodes Diode: a semiconductor device, which conduct the current
More informationInfrared Spectroscopy: Theory
u Chapter 15 Infrared Spectroscopy: Theory An important tool of the organic chemist is Infrared Spectroscopy, or IR. IR spectra are acquired on a special instrument, called an IR spectrometer. IR is used
More informationQuantum Mechanics and Atomic Structure 1
Quantum Mechanics and Atomic Structure 1 INTRODUCTION The word atom is derived from the Greek word, atomos, which means uncut or indivisible. It was Dalton (1808) who established that elementary constituents
More informationLecture 2 - Semiconductor Physics (I) September 13, 2005
6.012 - Microelectronic Devices and Circuits - Fall 2005 Lecture 2-1 Lecture 2 - Semiconductor Physics (I) September 13, 2005 Contents: 1. Silicon bond model: electrons and holes 2. Generation and recombination
More informationEnergy. Mechanical Energy
Principles of Imaging Science I (RAD119) Electromagnetic Radiation Energy Definition of energy Ability to do work Physicist s definition of work Work = force x distance Force acting upon object over distance
More informationQuantum Phenomena and the Theory of Quantum Mechanics
Quantum Phenomena and the Theory of The Mechanics of the Very Small Waseda University, SILS, Introduction to History and Philosophy of Science . Two Dark Clouds In 1900 at a Friday Evening lecture at the
More informationTheory of electrons and positrons
P AUL A. M. DIRAC Theory of electrons and positrons Nobel Lecture, December 12, 1933 Matter has been found by experimental physicists to be made up of small particles of various kinds, the particles of
More informationElectrons in Atoms & Periodic Table Chapter 13 & 14 Assignment & Problem Set
Electrons in Atoms & Periodic Table Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Electrons in Atoms & Periodic Table 2 Study Guide: Things You
More informationBlackbody radiation derivation of Planck s radiation low
Blackbody radiation derivation of Planck s radiation low 1 Classical theories of Lorentz and Debye: Lorentz (oscillator model): Electrons and ions of matter were treated as a simple harmonic oscillators
More informationCurriculum for Excellence. Higher Physics. Success Guide
Curriculum for Excellence Higher Physics Success Guide Electricity Our Dynamic Universe Particles and Waves Electricity Key Area Monitoring and Measuring A.C. Monitoring alternating current signals with
More informationSample Exercise 6.1 Concepts of Wavelength and Frequency
Sample Exercise 6.1 Concepts of Wavelength and Frequency Two electromagnetic waves are represented in the margin. (a) Which wave has the higher frequency? (b) If one wave represents visible light and the
More informationE/M Experiment: Electrons in a Magnetic Field.
E/M Experiment: Electrons in a Magnetic Field. PRE-LAB You will be doing this experiment before we cover the relevant material in class. But there are only two fundamental concepts that you need to understand.
More informationPreview of Period 3: Electromagnetic Waves Radiant Energy II
Preview of Period 3: Electromagnetic Waves Radiant Energy II 3.1 Radiant Energy from the Sun How is light reflected and transmitted? What is polarized light? 3.2 Energy Transfer with Radiant Energy How
More informationAstronomy 110 Homework #04 Assigned: 02/06/2007 Due: 02/13/2007. Name:
Astronomy 110 Homework #04 Assigned: 02/06/2007 Due: 02/13/2007 Name: Directions: Listed below are twenty (20) multiple-choice questions based on the material covered by the lectures this past week. Choose
More informationAtomic Structure: Chapter Problems
Atomic Structure: Chapter Problems Bohr Model Class Work 1. Describe the nuclear model of the atom. 2. Explain the problems with the nuclear model of the atom. 3. According to Niels Bohr, what does n stand
More informationAP* Atomic Structure & Periodicity Free Response Questions KEY page 1
AP* Atomic Structure & Periodicity ree Response Questions KEY page 1 1980 a) points 1s s p 6 3s 3p 6 4s 3d 10 4p 3 b) points for the two electrons in the 4s: 4, 0, 0, +1/ and 4, 0, 0, - 1/ for the three
More informationWaves-Wave Characteristics
1. What is the wavelength of a 256-hertz sound wave in air at STP? 1. 1.17 10 6 m 2. 1.29 m 3. 0.773 m 4. 8.53 10-7 m 2. The graph below represents the relationship between wavelength and frequency of
More informationCalculating particle properties of a wave
Calculating particle properties of a wave A light wave consists of particles (photons): The energy E of the particle is calculated from the frequency f of the wave via Planck: E = h f (1) A particle can
More information1. Basics of LASER Physics
1. Basics of LASER Physics Dr. Sebastian Domsch (Dipl.-Phys.) Computer Assisted Clinical Medicine Medical Faculty Mannheim Heidelberg University Theodor-Kutzer-Ufer 1-3 D-68167 Mannheim, Germany sebastian.domsch@medma.uni-heidelberg.de
More informationChemical Synthesis. Overview. Chemical Synthesis of Nanocrystals. Self-Assembly of Nanocrystals. Example: Cu 146 Se 73 (PPh 3 ) 30
Chemical Synthesis Spontaneous organization of molecules into stable, structurally well-defined aggregates at the nanometer length scale. Overview The 1-100 nm nanoscale length is in between traditional
More informationBoyle s law - For calculating changes in pressure or volume: P 1 V 1 = P 2 V 2. Charles law - For calculating temperature or volume changes: V 1 T 1
Common Equations Used in Chemistry Equation for density: d= m v Converting F to C: C = ( F - 32) x 5 9 Converting C to F: F = C x 9 5 + 32 Converting C to K: K = ( C + 273.15) n x molar mass of element
More informationScience Standard Articulated by Grade Level Strand 5: Physical Science
Concept 1: Properties of Objects and Materials Classify objects and materials by their observable properties. Kindergarten Grade 1 Grade 2 Grade 3 Grade 4 PO 1. Identify the following observable properties
More informationHeisenberg Uncertainty
Heisenberg Uncertainty Outline - Heisenberg Microscope - Measurement Uncertainty - Example: Hydrogen Atom - Example: Single Slit Diffraction - Example: Quantum Dots 1 TRUE / FALSE A photon (quantum of
More information5.1 Evolution of the Atomic Model
5.1 Evolution of the Atomic Model Studying the atom has been a fascination of scientists for hundreds of years. Even Greek philosophers, over 2500 years ago, discussed the idea of there being a smallest
More informationChem 1A Exam 2 Review Problems
Chem 1A Exam 2 Review Problems 1. At 0.967 atm, the height of mercury in a barometer is 0.735 m. If the mercury were replaced with water, what height of water (in meters) would be supported at this pressure?
More informationChapters 21-29. Magnetic Force. for a moving charge. F=BQvsinΘ. F=BIlsinΘ. for a current
Chapters 21-29 Chapter 21:45,63 Chapter 22:25,49 Chapter 23:35,38,53,55,58,59 Chapter 24:17,18,20,42,43,44,50,52,53.59,63 Chapter 26:27,33,34,39,54 Chapter 27:17,18,34,43,50,51,53,56 Chapter 28: 10,11,28,47,52
More informationELG4126: Photovoltaic Materials. Based Partially on Renewable and Efficient Electric Power System, Gilbert M. Masters, Wiely
ELG4126: Photovoltaic Materials Based Partially on Renewable and Efficient Electric Power System, Gilbert M. Masters, Wiely Introduction A material or device that is capable of converting the energy contained
More informationElectrons In Atoms Mr. O Brien (SFHS) Chapter 5 Standard 1D
Electrons In Atoms Mr. O Brien (SFHS) Chapter 5 Standard 1D Electrons in Atoms (std.1d) What are Bohr Models? planetary model in which the negatively-charged electrons orbit a small, positively-charged
More informationCode number given on the right hand side of the question paper should be written on the title page of the answerbook by the candidate.
Series ONS SET-1 Roll No. Candiates must write code on the title page of the answer book Please check that this question paper contains 16 printed pages. Code number given on the right hand side of the
More informationFrom lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?
From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation? From lowest energy to highest energy, which of the following correctly
More informationCharacteristic curves of a solar cell
Related Topics Semi-conductor, p-n junction, energy-band diagram, Fermi characteristic energy level, diffusion potential, internal resistance, efficiency, photo-conductive effect, acceptors, donors, valence
More informationPhotovoltaics photo volt Photovoltaic Cells Crystalline Silicon Cells Photovoltaic Systems
1 Photovoltaics Photovoltaic (PV) materials and devices convert sunlight into electrical energy, and PV cells are commonly known as solar cells. Photovoltaics can literally be translated as light-electricity.
More informationBasic Nuclear Concepts
Section 7: In this section, we present a basic description of atomic nuclei, the stored energy contained within them, their occurrence and stability Basic Nuclear Concepts EARLY DISCOVERIES [see also Section
More informationSOLAR CELLS From light to electricity
SOLAR CELLS From light to electricity This guide provides as accurate an explanation as possible of the complex phenomena behind the transformation of light into electricity. It also includes exercises
More informationRadiation Transfer in Environmental Science
Radiation Transfer in Environmental Science with emphasis on aquatic and vegetation canopy media Autumn 2008 Prof. Emmanuel Boss, Dr. Eyal Rotenberg Introduction Radiation in Environmental sciences Most
More information