Optical Properties of Condensed Matter and Applications (Wiley Series in Materials for Electronic & Optoelectronic Applications)

Following a semi-quantitative approach, this book presents a summary of the basic concepts, with examples and applications, and reviews recent developments in the study of optical properties of condensed matter systems. Key Features: Covers basic knowledge as well as application topics Includes theory, experimental techniques and current and developing applications Timely and useful contribution to the literature Written by internationally respected contributors working in physics and electrical engineering departments and government laboratories Contents 8 Series Preface 14 Preface 16 1: Fundamental Optical Properties of Materials I 18 1.1 INTRODUCTION 18 1.2 OPTICAL CONSTANTS 19 1.2.1 Refractive index and extinction coefficient 19 1.2.2 n and K, and Kramers–Kronig relations 22 1.3 REFRACTIVE INDEX AND DISPERSION 23 1.3.1 Cauchy dispersion relation 24 1.3.2 Sellmeier dispersion equation 24 1.3.3 Refractive index of semiconductors 27 1.3.4 Gladstone–Dale formula and oxide glasses 29 1.3.5 Wemple–DiDomenico dispersion relation 29 1.3.6 Group index 31 1.4 THE SWANEPEL TECHNIQUE: MEASUREMENT OF n AND a 31 1.4.1 Uniform-thickness films 31 1.4.2 Thin films with nonuniform thickness 36 1.5 CONCLUSIONS 40 2: Fundamental Optical Properties of Materials II 44 2.1 INTRODUCTION 44 2.2 LATTICE OR RESTSTRAHLEN ABSORPTION AND INFRARED REFLECTION 47 2.3 FREE CARRIER ABSORPTION (FCA) 48 2.4 BAND-TO-BAND OR FUNDAMENTAL ABSORPTION (CRYSTALLINE SOLIDS) 51 2.5 IMPURITY ABSORPTION 55 2.5.1 Optical absorption of trivalent rare earth ions: Judd–Ofelt analysis 55 2.5.2 Optical absorption cross-section 58 2.6 EFFECT OF EXTERNAL FIELDS 58 2.6.1 Electro-optic effects 58 2.6.2 Electro-absorption and Franz–Keldysh effect 59 2.6.3 Faraday effect 61 2.7 CONCLUSIONS 62 3: Optical Properties of Disordered Condensed Matter 64 3.1 INTRODUCTION 64 3.2 FUNDAMENTAL OPTICAL ABSORPTION (EXPERIMENTAL) 66 3.2.1 Amorphous chalcogenides 66 3.2.2 Hydrogenated nanocrystalline silicon (nc-Si:H) 70 3.3 ABSORPTION COEFFICIENT (THEORY) 71 3.4 COMPOSITIONAL VARIATION OF THE OPTICAL BANDGAP IN AMORPHOUS CHALCOGENIDES 77 3.5 CONCLUSIONS 78 4: Concept of Excitons 80 4.1 INTRODUCTION 80 4.2 EXCITONS IN CRYSTALLINE SOLIDS 81 4.2.1 Excitonic absorption in crystalline solids 84 4.3 EXCITONS IN AMORPHOUS SEMICONDUCTORS 86 4.3.1 Excitonic absorption in amorphous solids 88 4.4 CONCLUSIONS 90 5: Photoluminescence 92 5.1 INTRODUCTION 92 5.2 FUNDAMENTAL ASPECTS OF PHOTOLUMINESCENCE (PL) IN CONDENSED MATTER 93 5.3 EXPERIMENTAL ASPECTS 97 5.3.1 Static PL spectroscopy 97 5.3.2 Photoluminescence excitation (PLE) spectroscopy and photoluminescence absorption spectroscopy (PLAS) 99 5.3.3 Time-resolved spectroscopy (TRS) 100 5.3.4 Time-correlated single-photon counting (TCSPC) 103 5.3.5 Frequency-resolved spectroscopy (FRS) 104 5.3.6 Quadrature frequency-resolved spectroscopy (QFRS) 105 5.4 PHOTOLUMINESCENCE LIFETIME SPECTROSCOPY OF AMORPHOUS SEMICONDUCTORS BY QFRS TECHNIQUE 107 5.4.1 Overview 107 5.4.2 Dual-phase double lock-in (DPDL) QFRS technique 109 5.4.3 Exploring broad PL lifetime distribution in a-Si:H and a-Ge:H by wideband QFRS 112 5.4.4 Residual PL decay of a-Si:H 119 5.5 CONCLUSIONS 120 6: Photoluminescence and Photoinduced Changes in Noncrystalline Condensed Matter 124 6.1 INTRODUCTION 124 6.2 PHOTOLUMINESCENCE 126 6.2.1 Radiative recombination operator and transition matrix element 127 6.2.2 Rates of spontaneous emission 132 6.2.3 Results of spontaneous emission and radiative lifetime 138 6.2.4 Temperature dependence of PL 145 6.2.5 Excitonic concept 147 6.3 PHOTOINDUCED CHANGES IN AMORPHOUS CHALCOGENIDES 148 6.3.1 Effect of photo-excitation and phonon interaction 149 6.3.2 Excitation of a single electron–hole pair 151 6.3.3 Pairing of like excited charge carriers 152 6.4 CONCLUSIONS 155 7: Light-induced Volume Changes in Chalcogenide Glasses 160 7.1. INTRODUCTION 160 7.2 SIMULATION METHOD 162 7.3 SAMPLE PREPARATION 163 7.4 LIGHT-INDUCED PHENOMENA 167 7.4.1 Electron excitation 167 7.4.2 Hole creation 168 7.5 MACROSCOPIC MODELS 170 7.5.1 Ideal, reversible case (a-Se) 170 7.5.2 Nonideal, irreversible case (a-As2Se3) 171 7.6 CONCLUSIONS 174 8: Optical Properties of Glasses 176 8.1 INTRODUCTION 177 8.2 THE REFRACTIVE INDEX 177 8.3 GLASS INTERFACES 179 8.4 DISPERSION 182 8.5 SENSITIVITY OF THE REFRACTIVE INDEX 184 8.5.1 Temperature dependence 184 8.5.2 Stress dependence 185 8.5.3 Magnetic field dependence – the Faraday effect 185 8.5.4 Chemical perturbations – molar refractivity 188 8.6 GLASS COLOR 188 8.6.1 Coloration by colloidal metals and semiconductors 189 8.6.2 Optical absorption in rare-earth-doped glass 190 8.6.3 Absorption by 3d metal ions 193 8.7 FLUORESCENCE IN RARE-EARTH-DOPED GLASS 195 8.8 GLASSES FOR FIBRE OPTICS 198 8.9 REFRACTIVE INDEX ENGINEERING 200 8.10 TRANSPARENT GLASS CERAMICS 202 8.10.1 Introduction 202 8.10.2 Theoretical basis for transparency 204 8.10.3 Rare-earth-doped transparent glass ceramics for active photonics 207 8.10.4 Ferroelectric transparent glass ceramics 209 8.10.5 Transparent glass ceramics for X-ray storage phosphors 209 8.11 CONCLUSIONS 211 9: Properties and Applications of Photonic Crystals 214 9.1 INTRODUCTION 214 9.2 PC OVERVIEW 215 9.2.1 Introduction to PCs 215 9.2.2 Nano-engineering of PC architectures 217 9.2.3 Materials selection for PCs 219 9.3 TUNABLE PCs 220 9.3.1 Tuning PC response by changing the refractive index of constituent materials 220 9.3.2 Tuning PC response by altering the physical structure of the PC 222 9.4 SELECTED APPLICATIONS OF PC 225 9.4.1 Waveguide devices 226 9.4.2 Dispersive devices 227 9.4.3 Add/Drop multiplexing devices 227 9.4.4 Applications of PCs for LEDs and lasers 228 9.5 CONCLUSIONS 229 10: Nonlinear Optical Properties of Photonic Glasses 232 10.1 INTRODUCTION 232 10.2 PHOTONIC GLASS 234 10.3 NONLINEAR ABSORPTION AND REFRACTIVITY 236 10.3.1 Fundamentals 236 10.3.2 Two-photon absorption 239 10.3.3 Nonlinear refractivity 241 10.4 NONLINEAR EXCITATION-INDUCED STRUCTURAL CHANGES 243 10.4.1 Fundamentals 243 10.4.2 Oxides 244 10.4.3 Chalcogenides 246 10.5 CONCLUSIONS 248 11: Optical Properties of Organic Semiconductors and Applications 252 11.1 INTRODUCTION 252 11.2 MOLECULAR STRUCTURE OF p-CONJUGATED POLYMERS 253 11.3 THEORETICAL MODELS 254 11.4 ABSORPTION SPECTRUM 257 11.5 PHOTOLUMINESCENCE 260 11.6 NONEMISSIVE EXCITED STATES 264 11.7 ELECTRON–ELECTRON INTERACTION 266 11.8 INTERCHAIN INTERACTION 271 11.9 CONCLUSIONS 275 12: Organic Semiconductors and Applications 278 12.1 INTRODUCTION 278 12.1.1 OLED architecture and operation principle 279 12.1.2 Technical challenges and process integration 282 12.2 ANODE MODIFICATION FOR ENHANCED OLED PERFORMANCE 282 12.2.1 Low-temperature high-performance ITO 283 12.2.2 Anode modification 294 12.2.3 Electroluminescence performance of OLEDs 296 12.3 FLEXIBLE OLED DISPLAYS 301 12.3.1 Flexible OLEDs on ultra-thin glass substrate 301 12.3.2 Flexible top-emitting OLEDs on plastic foils 303 12.4 CONCLUSIONS 310 13: Optical Properties of Thin Films 314 13.1 INTRODUCTION 315 13.2 OPTICS OF THIN FILMS 315 13.2.1 An isotropic film on a substrate 315 13.2.2 Matrix methods for multi-layered structures 317 13.2.3 Anisotropic films 319 13.3 REFLECTION–TRANSMISSION PHOTOELLIPSOMETRY FOR OPTICAL-CONSTANTS DETERMINATION 320 13.3.1 Photoellipsometry of a thick or a thin film 320 13.3.2 Photoellipsometry for a stack of thick and thin films 323 13.3.3 Remarks on the reflection-transmission photoellipsometry method 325 13.4 APPLICATIONS OF THIN FILMS TO ENERGY MANAGEMENT AND RENEWABLE ENERGY TECHNOLOGIES 326 13.4.1 Electrochromic thin films 326 13.4.2 Pure and metal-doped VO2 thermochromic thin films 327 13.4.3 Temperature-stabilized V1-xWxO2 sky radiator films 329 13.4.4 Optical functional TiO2 thin film for environmentally friendly technologies 332 13.5 CONCLUSIONS 337 14: Negative Index of Refraction: Optics and Metamaterials 342 14.1 INTRODUCTION 342 14.1.1 Electric and magnetic response 343 14.1.2 Veselago’s slab lens and Pendry’s perfect lens 346 14.2 OPTICS OF PROPAGATING WAVES WITH NEGATIVE INDEX 349 14.2.1 Foundation in Fourier optics 349 14.2.2 Fermat’s principle in a slab lens 350 14.2.3 Ray tracing with negative index and aberrations 353 14.3 SUPER-RESOLUTION WITH THE SLAB LENS 355 14.3.1 Amplification of the evanescent waves 355 14.3.2 Aberrations in the evanescent image 362 14.3.3 Experimental results with evanescent waves 363 14.4 NEGATIVE REFRACTION WITH METAMATERIALS 365 14.5 CONCLUSIONS 369 15: Excitonic Processes in Quantum Wells 372 15.1 INTRODUCTION 372 15.2 EXCITON–PHONON INTERACTION 373 15.3 EXCITON FORMATION IN QUANTUM WELLS ASSISTED BY PHONONS 374 15.4 NONRADIATIVE RELAXATION OF FREE EXCITONS 382 15.4.1 Intraband processes 382 15.4.2 Interband processes 387 15.5 QUASI-2D FREE-EXCITON LINEWIDTH 393 15.6 LOCALIZATION OF FREE EXCITONS 399 15.7 CONCLUSIONS 407 16: Optical Properties and Spin Dynamics of Diluted Magnetic Semiconductor Nanostructures 410 16.1 INTRODUCTION 410 16.2 COUPLED QUANTUM WELLS 412 16.2.1 Spin injection 412 16.2.2 Spin separation and switching 414 16.2.3 Spin dynamics studied by pump-probe spectroscopy 417 16.3 NANOSTRUCTURES FABRICATED BY ELECTRON-BEAM LITHOGRAPHY 420 16.4 SELF-ASSEMBLED QUANTUM DOTS 424 16.5 HYBRID NANOSTRUCTURES WITH FERROMAGNETIC MATERIALS 427 16.6 CONCLUSIONS 430 Index 434 Contents......Page 8 Series Preface......Page 14 Preface......Page 16 1.1 INTRODUCTION......Page 18 1.2.1 Refractive index and extinction coefficient......Page 19 1.2.2 n and K, and Kramers–Kronig relations......Page 22 1.3 REFRACTIVE INDEX AND DISPERSION......Page 23 1.3.2 Sellmeier dispersion equation......Page 24 1.3.3 Refractive index of semiconductors......Page 27 1.3.5 Wemple–DiDomenico dispersion relation......Page 29 1.4.1 Uniform-thickness films......Page 31 1.4.2 Thin films with nonuniform thickness......Page 36 1.5 CONCLUSIONS......Page 40 2.1 INTRODUCTION......Page 44 2.2 LATTICE OR RESTSTRAHLEN ABSORPTION AND INFRARED REFLECTION......Page 47 2.3 FREE CARRIER ABSORPTION (FCA)......Page 48 2.4 BAND-TO-BAND OR FUNDAMENTAL ABSORPTION (CRYSTALLINE SOLIDS)......Page 51 2.5.1 Optical absorption of trivalent rare earth ions: Judd–Ofelt analysis......Page 55 2.6.1 Electro-optic effects......Page 58 2.6.2 Electro-absorption and Franz–Keldysh effect......Page 59 2.6.3 Faraday effect......Page 61 2.7 CONCLUSIONS......Page 62 3.1 INTRODUCTION......Page 64 3.2.1 Amorphous chalcogenides......Page 66 3.2.2 Hydrogenated nanocrystalline silicon (nc-Si:H)......Page 70 3.3 ABSORPTION COEFFICIENT (THEORY)......Page 71 3.4 COMPOSITIONAL VARIATION OF THE OPTICAL BANDGAP IN AMORPHOUS CHALCOGENIDES......Page 77 3.5 CONCLUSIONS......Page 78 4.1 INTRODUCTION......Page 80 4.2 EXCITONS IN CRYSTALLINE SOLIDS......Page 81 4.2.1 Excitonic absorption in crystalline solids......Page 84 4.3 EXCITONS IN AMORPHOUS SEMICONDUCTORS......Page 86 4.3.1 Excitonic absorption in amorphous solids......Page 88 4.4 CONCLUSIONS......Page 90 5.1 INTRODUCTION......Page 92 5.2 FUNDAMENTAL ASPECTS OF PHOTOLUMINESCENCE (PL) IN CONDENSED MATTER......Page 93 5.3.1 Static PL spectroscopy......Page 97 5.3.2 Photoluminescence excitation (PLE) spectroscopy and photoluminescence absorption spectroscopy (PLAS)......Page 99 5.3.3 Time-resolved spectroscopy (TRS)......Page 100 5.3.4 Time-correlated single-photon counting (TCSPC)......Page 103 5.3.5 Frequency-resolved spectroscopy (FRS)......Page 104 5.3.6 Quadrature frequency-resolved spectroscopy (QFRS)......Page 105 5.4.1 Overview......Page 107 5.4.2 Dual-phase double lock-in (DPDL) QFRS technique......Page 109 5.4.3 Exploring broad PL lifetime distribution in a-Si:H and a-Ge:H by wideband QFRS......Page 112 5.4.4 Residual PL decay of a-Si:H......Page 119 5.5 CONCLUSIONS......Page 120 6.1 INTRODUCTION......Page 124 6.2 PHOTOLUMINESCENCE......Page 126 6.2.1 Radiative recombination operator and transition matrix element......Page 127 6.2.2 Rates of spontaneous emission......Page 132 6.2.3 Results of spontaneous emission and radiative lifetime......Page 138 6.2.4 Temperature dependence of PL......Page 145 6.2.5 Excitonic concept......Page 147 6.3 PHOTOINDUCED CHANGES IN AMORPHOUS CHALCOGENIDES......Page 148 6.3.1 Effect of photo-excitation and phonon interaction......Page 149 6.3.2 Excitation of a single electron–hole pair......Page 151 6.3.3 Pairing of like excited charge carriers......Page 152 6.4 CONCLUSIONS......Page 155 7.1. INTRODUCTION......Page 160 7.2 SIMULATION METHOD......Page 162 7.3 SAMPLE PREPARATION......Page 163 7.4.1 Electron excitation......Page 167 7.4.2 Hole creation......Page 168 7.5.1 Ideal, reversible case (a-Se)......Page 170 7.5.2 Nonideal, irreversible case (a-As2Se3)......Page 171 7.6 CONCLUSIONS......Page 174 8: Optical Properties of Glasses......Page 176 8.2 THE REFRACTIVE INDEX......Page 177 8.3 GLASS INTERFACES......Page 179 8.4 DISPERSION......Page 182 8.5.1 Temperature dependence......Page 184 8.5.3 Magnetic field dependence – the Faraday effect......Page 185 8.6 GLASS COLOR......Page 188 8.6.1 Coloration by colloidal metals and semiconductors......Page 189 8.6.2 Optical absorption in rare-earth-doped glass......Page 190 8.6.3 Absorption by 3d metal ions......Page 193 8.7 FLUORESCENCE IN RARE-EARTH-DOPED GLASS......Page 195 8.8 GLASSES FOR FIBRE OPTICS......Page 198 8.9 REFRACTIVE INDEX ENGINEERING......Page 200 8.10.1 Introduction......Page 202 8.10.2 Theoretical basis for transparency......Page 204 8.10.3 Rare-earth-doped transparent glass ceramics for active photonics......Page 207 8.10.5 Transparent glass ceramics for X-ray storage phosphors......Page 209 8.11 CONCLUSIONS......Page 211 9.1 INTRODUCTION......Page 214 9.2.1 Introduction to PCs......Page 215 9.2.2 Nano-engineering of PC architectures......Page 217 9.2.3 Materials selection for PCs......Page 219 9.3.1 Tuning PC response by changing the refractive index of constituent materials......Page 220 9.3.2 Tuning PC response by altering the physical structure of the PC......Page 222 9.4 SELECTED APPLICATIONS OF PC......Page 225 9.4.1 Waveguide devices......Page 226 9.4.3 Add/Drop multiplexing devices......Page 227 9.4.4 Applications of PCs for LEDs and lasers......Page 228 9.5 CONCLUSIONS......Page 229 10.1 INTRODUCTION......Page 232 10.2 PHOTONIC GLASS......Page 234 10.3.1 Fundamentals......Page 236 10.3.2 Two-photon absorption......Page 239 10.3.3 Nonlinear refractivity......Page 241 10.4.1 Fundamentals......Page 243 10.4.2 Oxides......Page 244 10.4.3 Chalcogenides......Page 246 10.5 CONCLUSIONS......Page 248 11.1 INTRODUCTION......Page 252 11.2 MOLECULAR STRUCTURE OF p-CONJUGATED POLYMERS......Page 253 11.3 THEORETICAL MODELS......Page 254 11.4 ABSORPTION SPECTRUM......Page 257 11.5 PHOTOLUMINESCENCE......Page 260 11.6 NONEMISSIVE EXCITED STATES......Page 264 11.7 ELECTRON–ELECTRON INTERACTION......Page 266 11.8 INTERCHAIN INTERACTION......Page 271 11.9 CONCLUSIONS......Page 275 12.1 INTRODUCTION......Page 278 12.1.1 OLED architecture and operation principle......Page 279 12.2 ANODE MODIFICATION FOR ENHANCED OLED PERFORMANCE......Page 282 12.2.1 Low-temperature high-performance ITO......Page 283 12.2.2 Anode modification......Page 294 12.2.3 Electroluminescence performance of OLEDs......Page 296 12.3.1 Flexible OLEDs on ultra-thin glass substrate......Page 301 12.3.2 Flexible top-emitting OLEDs on plastic foils......Page 303 12.4 CONCLUSIONS......Page 310 13: Optical Properties of Thin Films......Page 314 13.2.1 An isotropic film on a substrate......Page 315 13.2.2 Matrix methods for multi-layered structures......Page 317 13.2.3 Anisotropic films......Page 319 13.3.1 Photoellipsometry of a thick or a thin film......Page 320 13.3.2 Photoellipsometry for a stack of thick and thin films......Page 323 13.3.3 Remarks on the reflection-transmission photoellipsometry method......Page 325 13.4.1 Electrochromic thin films......Page 326 13.4.2 Pure and metal-doped VO2 thermochromic thin films......Page 327 13.4.3 Temperature-stabilized V1-xWxO2 sky radiator films......Page 329 13.4.4 Optical functional TiO2 thin film for environmentally friendly technologies......Page 332 13.5 CONCLUSIONS......Page 337 14.1 INTRODUCTION......Page 342 14.1.1 Electric and magnetic response......Page 343 14.1.2 Veselago’s slab lens and Pendry’s perfect lens......Page 346 14.2.1 Foundation in Fourier optics......Page 349 14.2.2 Fermat’s principle in a slab lens......Page 350 14.2.3 Ray tracing with negative index and aberrations......Page 353 14.3.1 Amplification of the evanescent waves......Page 355 14.3.2 Aberrations in the evanescent image......Page 362 14.3.3 Experimental results with evanescent waves......Page 363 14.4 NEGATIVE REFRACTION WITH METAMATERIALS......Page 365 14.5 CONCLUSIONS......Page 369 15.1 INTRODUCTION......Page 372 15.2 EXCITON–PHONON INTERACTION......Page 373 15.3 EXCITON FORMATION IN QUANTUM WELLS ASSISTED BY PHONONS......Page 374 15.4.1 Intraband processes......Page 382 15.4.2 Interband processes......Page 387 15.5 QUASI-2D FREE-EXCITON LINEWIDTH......Page 393 15.6 LOCALIZATION OF FREE EXCITONS......Page 399 15.7 CONCLUSIONS......Page 407 16.1 INTRODUCTION......Page 410 16.2.1 Spin injection......Page 412 16.2.2 Spin separation and switching......Page 414 16.2.3 Spin dynamics studied by pump-probe spectroscopy......Page 417 16.3 NANOSTRUCTURES FABRICATED BY ELECTRON-BEAM LITHOGRAPHY......Page 420 16.4 SELF-ASSEMBLED QUANTUM DOTS......Page 424 16.5 HYBRID NANOSTRUCTURES WITH FERROMAGNETIC MATERIALS......Page 427 16.6 CONCLUSIONS......Page 430 Index......Page 434

semiconductors Of Reduced Dimensionality (e.g. Quantum Wells, Superlattices, Arrays Of Quantum Wires And Quantum Dots) Exhibit Many Physical Properties Not Found In Bulk Materials. These Systems Are Of Interest For Fundamental Studies And For Technological Applications. Optical Methods Are Used For The Quantitative Determination Of The Electronic Band Structure Of Such Solids. Advances Made To Date In Photonic Devices That Have Enabled Optical Communications Could Not Have Been Achieved Without The Proper Understanding Of The Optical Properties Of Materials And How These Properties Influence The Overall Device Performance.

following A Semiquantitative Approach, This Book Summarizes The Basic Concepts, With Examples And Applications, And Reviews Some Recent Developments In The Study Of Optical Properties Of Condensed Matter Systems. It Covers Examples And Applications In The Field Of Electronic And Optoelectronic Materials, Including Organic Polymers, Inorganic Glasses, And Photonic Crystals. An Attempt Is Made To Cover Both The Experimental And Theoretical Developments In Any Field Presented In This Book. The Book Consists Of 16 Chapters Contributed By Experienced And Well-known Scientists And Groups On Different Aspects Of Optoelectronic Properties Of Condensed Matter. Most Chapters Are Presented To Be Relatively Independent With Minimal Cross Referencing And Chapters With Complementary Contents Are Arranged Together To Facilitate A Reader With Cross Referencing, If Desired.

it Is Intended Here To Have A Single Volume Covering From Fundamentals To Applications, With Up-to-date Advances In The Field, And A Book That Is Useful To Practitioners. Accomplishments And Technical Challenges In Device Applications Are Also Discussed. The Readership Of The Book Is Expected To Be Senior Undergraduate And Postgraduate Students, R&d Staff And Teaching And Research Professionals.