Course Syllabus for English-Taught Majors

“The Fundamentals of Photoelectric Materials and Instruments” Course Syllabus

 

Course Code09040011

Course CategoryMajor Elective

MajorsChemical Engineering, Chemistry

SemesterSpring

Total Hours36 Hours         Credit2 Credits

Lecture Hours36 Hours          Lab Hours0 Hours        Practice Hours0 Hours

Instructors

TextbooksAn Introduction to the Optical Spectroscopy of Inorganic Solids, J. Garc´ıa Sol´e, L.E. Baus´a and D. Jaque, Universidad Aut´onoma de Madrid, Madrid, Spain

Optical Properties of Solids, MARK FOX, Department of Physics and Astronomy, University of Sheffield

References

(1)Fox, M., Optical Properties of Solids, Oxford University Press, Oxford (2001).

(2)Demtr¨oder,W., Laser Spectroscopy, 3rd edn, Springer Series in Chemical Physics 5, Springer-

Verlag, Berlin (2003).

(3) Kuzmany, H., Solid State Spectroscopy. An Introduction, Springer-Verlag, Berlin (1998).

(4) Weber, M. J., Handbook of Optical Materials, CRC Press, Boca Raton, Florida (2003).

(5) Daran, E., Legros, R., Mu˜noz-Yag¨ue, A., and Baus´a, L. E., J. Appl. Phys., 76(1), 270 (1994).

(6) Fern´andez, J., Mendioroz, A., Garc´ıa, A. J., Balda, R., and Adam, J. L., Phys. Rev. B, 5(5),

3213 (2000).

(7)Blundell,S.(2001).Magnetism in condensed mater physics. Clarendon Press, Oxford.

(8)Lorrain P., Corson D.R. and Lorrain F. (2000). Fundamentals of electromagnetic phenomena. W.H. Freeman, Basingstoke.

(9)Corney, Alan(1977). Atomic and laser spectroscopy. Clarendon Press, Oxford.

(10)Harrison, W. (1999). Elementary electronic structure. World Scientific, Singapore.

(11)Bhattacharya, P. (1997), Semiconductor optoelectronic devices (2nd edn). Prentice Hall, New Jersey

(12)Helm, M(2000). Long wavelength infrared emitters based on quantum wells and superlattices. Gordon and Breach, Amsterdam.

(13)Nakamura, F., Peartron S. and Fasol, G. (2000). The blue laser diode (2nd edn), Springer-Verlag, Berlin.

(14)Liu, H.C and Capasso, F. (2000a). Intersubband transitions in quantum wells: physics and device applications , Semiconductors and Semimetals, Vol. 62 (series eds R.K. Willardson and E.R. Weber). Academic Press, San Diego.

(15) Liu, H.C and Capasso, F. (2000b). Intersubband transitions in quantum wells: physics and device applications , Semiconductors and Semimetals, Vol. 66 (series eds R.K. Willardson and E.R. Weber). Academic Press, San Diego.

Teaching Aim

    This courseThe fundamentals of photoelectric materials and instruments instructs the students from the Intensive Training Class and Engineering Class in the most basic aspects to be initiated into the field of the optical spectroscopy of solids, such as the propagation of light, Light Sources, Monochromators and Detectors, The Optical Transparency of Solids, Optically Active Centers, Applications: Rare Earth and Transition Metal Ions, and Color Centers. etc. The main purpose of this course is to help the students who are major in Chemistry and Chemical Engineering to form a way in which they can be used to thinking of, analyzing, and solving problems by combining the knowledge of chemistry and physics. Besides, in this course, all the topics and their consequences are taught at a step by step developing level in order to ensure that students with different starting levels can be familiar with this field as soon as possible and keep on making more and more progress. The emphasis is on clear physical principles of symmetry, quantum mechanics, and electromagnetism which underlie the whole field. At the same time, the subjects are related to real measurements and to the experimental techniques and devices currently used by physicists in academe and industry, which is aimed to make the course more practical for students’ further development.

 

Chapter One  Fundamentals

   Lecture Time: The first week; Lecture Hours: 2 Hours

Contents

       1.The Origins of Spectroscopy

              a. Self-introduction of the teachers

              b. Inform the students of what they can learn in this class

              c. Tell the students the rules of evaluation

       2.The Electromagnetic Spectrum and Optical Spectroscopy

              a. The quantization equation: E= E=hν=hc/ν=hc¯, h is Planck’s constant,     and h=6.02*10^(-34)

              b. Three different phenomena when light interacts with substance: Absorbing, Reflecting, Scattering.

       3.Absorption

              a. Absorption coefficient: dI = −αI dx

              b. Lambert-Beer’s Law: I = I0e^(−αx)

              c. The measurement of absorption spectra: the spectrophotometer

              d. Optical density: OD=log(I0/I)

              e. The relationship between Absorption coefficient and optical densityα=       (OD)/(x log e)=     2.303(OD)/x

              f. Absorbance: A=1-I/I0=1 – 10^(−OD)

              g. Transmittance: T = 10^(−OD)

              h. Reflectivity: R=IR/I0

                            i. The measurement of reflectivity

       4.Luminescence

              a. Different types of luminescence: Photoluminescence, cathodoluminescence, radioluminescence.etc

              b. The Measurement of Photoluminescence: the Spectrofluorimeter

              c. Luminescent efficiency: Iem = η(I0 − I )

              d. Stokes and Anti-Stokes Shifts

              e. Time-resolved luminescence

              f. The quantum efficiency η:η = A/(A + Anr)= τ/τ0

       5.The Raman Effect

              a. The principle of Raman Scattering: inelastic scattering

              b. Stokes lines and Anti-Stokes lines

Chapter Two  Light Sources

   Lecture Time: The second week; Lecture Hours: 2 Hours

Contents

       1. Thermal Radiation and Planck’s Law

              a. Higher temperature leads to shorter wavelength and stronger intensity.

              b. Stefan–Boltzmann law: Etot = σT4, Stefan–Boltzmann constant:σ=5.67     × 10−8 Wm−2 K−4

       2. Various lamps

              a. The definitions, principles and main characteristics of tungsten and quartz    halogen lamps

              b. The principle, main characteristics, main materials and emission spectra of   different spectral lamps

              c. The schematic design and wavelength range of a fluorescent lamp

              d. The principle and main characteristics of high-pressure discharge vapor        lamps

       e. The definition and main applications of solid state lamps

       3. Basic concepts of laser

              a. The word Laser is short for Light Amplification by Stimulated Emission of   Radiation

              b. The main characteristics of Laser: The large spectral density of power, The small divergence of the radiation beam, The narrow spectral width, The        possibility of continuously tuning the wavelength, The possibility of pulsed lasers    supplying intense short and ultra-short pulses up to the femtosecond range, Beneficial        in dealing with the phenomena that occur when many mutually coherent waves are superimposed

              c. The schematic design of a laser: an active medium, a pumping process, an   optical resonator system

              d. The explanation of the principle of the resonator

       4. Different types of lasers

              a. The mechanism of the excimer lasers

              b. The main principle and some common materials of gas lasers

              c. The main characteristics of dye lasers and the absorption and fluorescence

       spectra of a dye in a liquid solution

              d. The structure of semiconductor lasers and their working mechanism

              e. Common solid state lasers(Al2O3:Cr3+, Nd:YAG.etc) and their energy levels

       5. The tunability of laser radiation

              a. The mechanism of tunable solid state lasers

              b. A simplified energy-level diagram for a vibronic laser

Chapter Three  Monochromators and Detectors

   Lecture Time: The third week; Lecture Hours: 2 Hours

Contents

       1. Monochromators

              a. The definition of monochromators

              b. The two main utilities of monochromators in optical spectroscopy experiments

              c. The schematic drawing of the simplest kind of monochromator

              d. The main components of a monochromator: a variable entrance slit,     monochromator optics,a dispersive element, a variable exit slit

              e. The main parameters that are used to characterize any monochromator: the      spectral resolution, Bandpass, The spectral response: ‘blaze’, Dispersion

       2. Detectors

              a. The basic parameters of a detector: The spectral operation range, responsivity, The time constant (τ ), The noise equivalent power (NEP), The      detectivity, The specific detectivity

              b. Different types of detectors: Thermal detectors, Photoelectric detectors

       3. The Photomultiplier

              a. The working principles of a photomultiplier

              b. The schematic drawing of a photomultiplier

       of pulsed radiation

              c. Two main causes of this dispersion

              d. Noise in photomultipliers

       4. Optimization of the Signal-to-Noise Ratio

             a. The averaging procedure

              b. The Lock-In amplifier

Chapter Four  The Optical Transparency of Solids

   Lecture Time: The fourth and fifth weeks; Lecture Hours: 4 Hours

Contents

       1. Optical Magnitudes and the Dielectric Constant

              a. The complex refractive index, N: N = n + iκ

              b. The extinction coefficient,κ: α=2ωκ/c

              c. The relative dielectric constant of the material: ε1 = n2κ2, ε2 = 2nκ

              d. n and κ as functions of the relative dielectric constant: \

                     n=[1/2(ε12+ε22)1/2+ε1] 1/2

                                          κ=[1/2(ε12+ε22)1/2-ε1] 1/2

                            e. R=[(1-n)2+κ2]/ [(1+n)2+κ2]

       2. Metals

              a. The restoring force on the valence electrons: Drude model

              b. The definition of ideal metals: no damping forces

              c. The damping effect in real metals

       3. Semiconductors and Insulators

              a. The definition of semiconductors and insulators

              b. The energy bands of an insulator

              c. The explanation of the band structure diagram of Si

       4. The Spectral Shape of the Fundamental Absorption Edge

              a. The explanation of interband transitions in solids

              b. The definition of direct transition and indirect transition

              c. The absorption edge for direct transitions: the room temperature absorption   spectrum of InAs in the fundamental absorption edge region

              d. The absorption edge for indirect transitions:

              e. An analysis of the absorption edge of Ge

       5. Excitons

              a. The definition and formation of excitons

              b. The energy levels of an exciton

              c. Two basic types of excitons can occur in crystalline materials: weakly bound       (Mott–Wannier) excitons, tightly bound (Frenkel) excitons

              d. The formation of weakly bound (Mott–Wannier) excitons

              e. The explanation of the absorption spectrum of cuprous oxide

              f. The formation of tightly bound (Frenkel) excitons

              g. The explanation of absorption spectra of sodium chloride and lithium fluoride

Chapter Five  Optically Active Centers

   Lecture Time: The sixth and seventh weeks; Lecture Hours: 4 Hours

Contents

       1. Brief introduction

              a. The definition of optically active centers

              b. The optical features of a center depend on the type of dopant.

              c. The scheme of an illustrative optical center, AB6

       2. Static Interaction

              a. The static electric field is commonly called the crystalline field.

              b. The energy level can be solved by Schrodinger equation, Hψi = Eiψi

                            c. The energy of free ion in crystalline field:

                     H=HFI+HCF

                     HFI: the Hamiltonian related to the free ion A

                     HCF: the crystal field Hamiltonian accounting for the interaction of the             valence electrons of A with the electrostatic crystal field created by the B ions

              d. The energy of free ion applying quantum mechanical perturbation theory:                          HFI=H0+HEE +HSO

                                          H0: the central field Hamiltonian

                     Hee: a term that takes into accounting for any perturbation due to the         Coulomb interactions among the outer (valence) electrons

                     HSO: the spin–orbit interaction summed over these electrons

              e. Weak crystalline field: HCF<<HSO, Hee

                            f. Intermediate crystalline field: HCF<<HSO<Hee

                            g. Strong crystalline field: HSO<Hee<HCF

                            h. The crystalline field on d1 optical ions

              i. Different types of arrangement of ligands: octahedral, tetrahedral, cubic

              j. The application of molecular orbital theory in an octahedral AB6 center

       3. Band Intensities

              a. The factors effecting the absorption probability: incoming light intensity and the matrix element, μi f

                            b. Allowed transitions when initial and final states have opposite parity

              c. Forbidden transitions when initial and final states have equal parity

       4. Dynamic Interaction: The Configurational Coordinate Diagram

              a. The Schrodinger’s Equation applied in dynamic interaction:

                     H = HFI + HCF + HL

                                          HL: the Hamiltonian describing the lattice

              b. The side-band spectrum is essentially coincident with the Raman spectrum of      lithium niobate.

              c. Two examples of dynamic induced band-shape effects: Weak coupling and   strong coupling.

              d. The configurational coordinate diagram for theAB6 center oscillating as a     breathing mode

              e. The energy of harmonic oscillator at frequency Ω: En =(n+1/2) ¯hΩ

       5. Band Shape: The Huang–Rhys Coupling Parameter

              a. The configurational coordinate diagram with which to analyze transitions     between two electronic states

              b. The symmetry of absorption plot and emission plot

              c. The character of Huang-Rays parameter: a measurement of the Stokes shift

              d. The low-temperature band shape

       6. Nonradiative Transitions

              a. Multiphonon emission

              b. Energy transfer: Förster (Coulombic), Dexter(e- exchange)

              c. The concentration quenching of luminescence

Chapter Six  Applications: Rare Earth and Transition Metal Ions, and Color Centers

   Lecture Time: The eighth week; Lecture Hours: 2 Hours

Contents

       1. Rare Earth Ions

              a. The applications of rare earth ions: phosphors, lasers, and amplifiers.etc

              b. Trivalent rare Earth Ions: the Dieke Diagram

              c. The energy-level diagram for trivalent lanthanide rare earth ions in lanthanum

       chloride

              d. Divalent rare earth ions

              e. The two broad bands in the spectrum of Eu2+ ion in NaCl

       2. Nonradiative Transitions in Rare Earth Ions: The ‘Energy-Gap’ Law

              a. The relationship between energy gap and multiphonon emission rate:

                     Anr = Anr(0) × e−(α¯hΩ)p

                            b. The measured values of the nonradiative rate, Anr as a function of the energy        gap for different trivalent rare earth ions in three host crystals

       3. Transition Metal Ions

              a. The most common transition metal ions and their corresponding numbers (n)       of 3d valence electrons

              b. The absorption and emission spectra of 3d1 ions

              c. 3dn ions: Sugano–Tanabe Diagrams

              d. The absorption and emission spectra of ruby

              e. The room temperature luminescence of the Cr3+ ion in different host crystals

              f. The laser wavelength ranges covered by several transition metal ions when   they are incorporated in different crystals

       4. Color centers

              a. Four typical color centers in alkali halide crystals: F, FA, F­2, F­2+

              b. Wider variety of colour centers, greater versatility in production of       luminescent system

              c. The energy levels of an electron in a colour center solved by quantum   mechanics: En = h2 (n2x+ n2y+ n2z) /8m0(2a)2

                            d. The lowest energy transition of the F center: EF = 3h2/(8m0(2a)2)

Chapter Seven    Brief Summery and Introduction

 Lecture Time: The tenth week; Lecture Hours: 2 Hours

 Contents

1.       Classification of Optical Processes

a. The three simplest group, reflection, propagation and transmission.

b. The phenomenon that can occur while light propagates through an optical medium.

c. Details about refraction, absorption, luminescence, scattering.

1.1          Optical Coefficient

a. The coefficient of reflection(reflectivity)

R=IR/I0

b. Transmittance: T = 10^(−OD)

c. Absorbance: A=1-I/I0=1 – 10^(−OD)

d. Scattering cross-section and Rayleigh scattering

1.2          The complex refractive index and dielectric constant

a. Concepts of complex refractive index

N = n + iκ, and the physical meaning of n and κ

b. The extinction coefficient,κ: α=2ωκ/c

c. The relative dielectric constant of the material: ε1 = n2 − κ2, ε2 = 2nκ

d. n and κ as functions of the relative dielectric constant:

n=1/2(ε12+ε22)1/2+ε1 1/2

κ=1/2(ε12+ε22)1/2-ε1 1/2

e. R=(1-n)2+κ2/ (1+n)2+κ2

1.3          Optical materials

a. Crystalline insulators and semiconductors

use crystalline sapphire as an example

b. Glasses

c. Metals

the shiny characteristic optical feature

d. Molecular materials

e. Doped glasses and insulator

1.4           Characteristic optical physics in the solid state

a. Crystal symmetry

Any macroscopic physical property must have at least the symmetry of the crystal structure.

b. Electronic bands

Bloch’s theorem

c. Vibronic bands

 

Chapter Eight    Classical Propagation

 Lecture Time: The eleventh week; Lecture Hours: 1 Hour

 Contents

1.       Propagation of light in a dense optical medium

a. The three oscillators, bound electrons, vibrational oscillation and free electron oscillators.

b. Details about bound electrons, vibrational oscillation and free electron oscillators.

1.1          The dipole oscillator model

a. The Lorentz oscillator

b. Multiple resonances

c. The Kramers-Kronig relationships

 

Chapter Nine Interband absorption

 Lecture Time: The eleventh and twelfth week; Lecture Hours: 3 Hours

 Contents

1.       Interband transitions

a. Obtain a good understanding of the frequency dependence of the refractive index and absorption coefficient.

b. The energy diagram of two separated bands in a solid.

c. Electrons and holes.

d. The direct and indirect band gap

and how to distinguish between them.

1.1          The transition rate for direct absorption

a. How the matrix element M works.

b. The definition of density of states.

1.2          Band edge absorption in direct gap semiconductors

a. The atomic physics of the interband transitions

use the schematic diagram of the electron levels

b. The band structure of a direct gap semiconductor

c. The frequency dependence of the band edge absorption

the straight line relationship between a^2 and (hw-Eg).

d. The Franz-Keldysh effect

1.3          Band edge absorption in indirect gap semiconductors

a. The absorption of GaAs

the straight line relationship between a and (hw-Eg) ^2.

1.4           Semiconductor photodetectors

a. Photodiode

The schematic diagram of a photodiode detector and the quantum efficiency.

The several criteria.

b. Photoconductive devices

c. Photovoltaic devices

 

Chapter Ten Excitons

 Lecture Time: The thirteenth week; Lecture Hours: 2 Hours

 Contents

1.       The concept of excitons

a. Two kinds of excitons, Wannier-Mott excitons and Frenkel excitons.

b. The formation of two kinds of excitons and how to distinguish between them.

1.1          Details about free excitons

a. Its binding energy and radius.

b. The exciton absorption.

c. Free excitons at high densities.

Mott density.

1.2          Details about Frenkel excitons

a. Rare gas crystals

b. Alkali halides

the relationship in Eg, E1 and Eb

explain why the excitons are observed so strongly.

The explanation of absorption spectra of sodium chloride and lithium fluoride.

c. Molecular crystals

important in conjugated polymers, such as PDA.

 

Chapter Eleven Luminescence

 Lecture Time: The fourteenth week; Lecture Hours: 2 Hours

 Contents

1.       Light emission in solid

a. The definitions and relationship of photoluminescence and electroluminescence.

the radiative lifetime, how to calculate and how to use it to solve actual problems.

1.1          Interband luminescence

a. Direct gap materials.

how do these materials work and learn to read luminescence spectrum

b. Indirect gap materials.

Example 5.1

1.2          Photoluminescence

a. Excitation and relaxation

learn the schematic diagram of the processes and the density of states

b. Low carrier density

1.3          Electroluminescence

a. General principles of electroluminescent devices

the main factors that determine the choice of the material,

the size of the band gap

constraints relating to lattice matching

the ease of p-type doping.

b. Light emitting diodes

Chapter Twelve Semiconductor quantum wells

 Lecture Time: The fifteenth week; Lecture Hours: 2 Hours

 Contents

1.       Quantum confined structures

a. Introduction about quantum confinement effect

quantum wells

quantum wires

quantum dots

b. Use Heisenberg uncertainty principle to calculate the confined region

1.1          Growth and structure of semiconductor quantum wells

a. Molecular Beam Epitaxy(MBE)

b. Metal-Organic Vapour Phase Epitaxy(MOVPE)

c. Metal-Organic Chemical Vapour Deposition(MOCVD)

d. The growth and Eg of the quantum wells

1.2           Electronic levels

a. Separation of the variables

b. Infinite potential wells and finite potential wells

approaches to solve the equations

1.3          Optical absorption and excitons

a. Brief introduction about selection rules

Fermi’s golden rule

b. Experimental data

combined with the knowledge of excitons

1.4           The Optical emission

a. The luminescence spectrum consists of a peak at the band gap energy with a width determined by the carrier density and the temperature.

1.5           Quantum dots

a. Variation of the electron density of states with dimensionality.

b. Absorption spectra of glasses with CdS microcrystals of varying size at 4.2K.

 

 Chapter Thirteen Molecular materials

 Lecture Time: The sixteenth week; Lecture Hours: 2 Hours

Contents

1.       Introduction to molecular materials

a. Aromatic hydrocarbons

b. Conjugated polymers

c. Electronic states in conjugated molecules

molecular orbital, LUMO, HOMO

1.1          Optical spectra of molecules

a. Understand the concept of vibrational-electronic transitions

use the schematic diagram to illustrate the notions

b. Electronic-vibrational transitions

the cause of Stokes shift

c. Molecular configuration diagrams

based on Born-Oppenheimer approximation

d. The Franck-Condon principle

The electronic transitions take place so rapidly that the nuclei do not move significantly during the transition.

use the absorption spectrum of ammonia in the UV spectral region to illustrate the idea.

 

 Chapter Fourteen Luminescence Centres

 Lecture Time: The seventeenth week; Lecture Hours: 1 Hour

Contents

1.       Color centres

a. Four typical color centers in alkali halide crystals: F, FA, F­2, F­2+

b. Wider variety of colour centers, greater versatility in production of  luminescent system

c. The energy levels of an electron in a colour center solved by quantum  mechanics: En = h2 (n2x+ n2y+ n2z) /8m0(2a)2

d. The lowest energy transition of the F center: EF = 3h2/(8m0(2a)2)

1.1          Rare Earth Ions

a. The applications of rare earth ions: phosphors, lasers, and amplifiers.etc

b. Trivalent rare Earth Ions: the Dieke Diagram

c. The energy-level diagram for trivalent lanthanide rare earth ions in lanthanum

chloride

d. Divalent rare earth ions

e. The two broad bands in the spectrum of Eu2+ ion in NaCl

1.2          Transition Metal Ions

a. The most common transition metal ions and their corresponding numbers (n) of 3d valence electrons

b. The absorption and emission spectra of 3d1 ions

c. 3dn ions: Sugano–Tanabe Diagrams

d. The absorption and emission spectra of ruby

e. The room temperature luminescence of the Cr3+ ion in different host crystals

f. The laser wavelength ranges covered by several transition metal ions when they are incorporated in different crystals

 

Chapter Fifteen Phonons

 Lecture Time: The seventeenth week; Lecture Hours: 1 Hour

Contents

1.       Infrared active phonons

a. Differences between acoustic and optical phonons

b. Differences between transverse and longitudinal phonons

1.1          Infrared reflectivity and absorption in polar solids

a. The classical oscillator model

b. The lattice absorption

1.2          Introduction of polaritons and polarons

1.3           Different kinds of scattering

 

 

Assessment Methods

 Daily scores: 20% (Answer questions in class; at least three questions per students)

 Mid-term examination: 20%

 Final examination: 60%

 

                                             Made by Hongtao Sun/Yue Pan

                                           Date:     _____2016______10_____25_