Upconverting Nanoparticles: From Fundamentals to Applications

Modern learning resource providing broad coverage of the rapidly-advancing field of upconverting nanoparticles This modern reference explains photon upconversion technology using nanoparticles from first principles to novel and future applications in imaging, sensing, catalysis, energy technology, biomedicine, and many other areas. Expert authors discuss both established and novel materials and applications, going far beyond the coverage of previously published books on the subject. Key topics covered in the book include: Synthesis, characterization, and basic properties of nanoparticles with photon-upconverting properties New types of upconverting nanoparticles, including transition metal- and rare earth-doped materials, metal-organic frameworks, core/shell particles, and surface-modified particles Current and emerging application areas for upconverting nanoparticles, including heating, lighting, sensing, and detection Biomedical uses of nanoparticles, including photodynamic therapy Photon upconversion using nanoparticles has opened the door to a new universe of light-powered technology. This book is a key resource for scientists, physicists, and chemists across a wide range of disciplines who wish to master the theory, methods and applications of this powerful new technology.

Table of Contents:
Preface xv 1 Introduction to Upconversion and Upconverting Nanoparticles 1 Manisha Mondal and Vineet Kumar Rai 1.1 Introduction 1 1.2 Frequency Conversion and Its Various Processes 2 1.2.1 Stokes Emission 2 1.2.2 Anti-Stokes Emission 2 1.2.2.1 Ground/Excited-State Absorption (GSA/ESA) 3 1.2.2.2 Energy Transfer Upconversion (ETU) 4 1.2.2.3 Cooperative Luminescence and Cooperative Sensitization Upconversion (csu) 5 1.2.2.4 Cross-relaxation (CR) and Photon Avalanche (PA) 6 1.3 Transition Metals and Their Properties 7 1.4 Rare Earths and Their Properties 8 1.4.1 Trivalent Rare-Earth Ions 9 1.4.1.1 Electronic Structure 9 1.4.1.2 Interaction of Rare-Earth Ions 10 1.4.1.3 Dieke Diagram 13 1.4.2 Divalent Rare-Earth Ions 13 1.5 Excitation and De-excitation Processes of Rare Earths in Solid Materials 15 1.5.1 Excitation Processes 15 1.5.1.1 f–f Transition 15 1.5.1.2 f–d Transition 15 1.5.1.3 Charge Transfer Transition 15 1.5.2 Emission Processes 15 1.5.2.1 Emission via Radiative Transitions 15 1.5.2.2 Emission via Nonradiative Transitions 16 1.5.2.3 Energy Transfer Processes 16 1.6 Rate Equations Relevant to UC Mechanism 18 1.6.1 Rate Equations in a Basic Three-Level System 18 1.6.2 Rate Equation Related to Pump Power-Dependent UC Emission 19 1.7 Theoretical Description of Optical Characteristics of Rare-Earth Ions 20 1.7.1 Judd–Ofelt (J–O) Theory and Calculation of Radiative Parameters 21 1.7.2 Nephelauxetic Effect 22 1.8 An Introduction to Upconverting Nanoparticles 22 Acknowledgments 23 References 23 2 Synthesis Protocol of Upconversion Nanoparticles 31 Lakshmi Mukhopadhyay and Vineet Kumar Rai 2.1 Introduction 31 2.2 Host Matrix 32 2.3 Synthetic Strategy of UC Nanomaterials 33 2.3.1 Solid-State Reaction Technique 34 2.3.2 Coprecipitation Technique 35 2.3.3 Sol–Gel Technique 36 2.3.4 Hydro(solvo)thermal Technique 39 2.3.5 Combustion Technique 40 2.3.6 Thermolysis Technique 42 2.3.6.1 Thermolysis in OA-Based Mixed Solvents 43 2.3.6.2 Thermolysis in OM-Based Mixed Solvents 43 2.3.6.3 Thermolysis in TOPO-Based Mixed Solvents 43 2.3.7 Microwave-Assisted Synthesis Technique 44 2.4 Synthesis Techniques for Fabricating Core@shell Architectures 45 2.4.1 Solid-Phase Reaction 45 2.4.2 Liquid-Phase Reaction 46 2.4.2.1 Stöber Technique 46 2.4.2.2 Microemulsion Technique 48 2.4.3 Gas-Phase Reaction 51 2.4.4 Mechanical Mixing 52 2.5 Other Synthesis Strategies to Develop Lanthanide-Doped UCNPs 52 2.6 Conclusion 53 References 53 3 Characterization Techniques and Analysis 67 Neha Jain, Prince K. Jain, Rajan K. Singh, Amit Srivastava, and Jai Singh 3.1 Introduction 67 3.2 X-Ray Diffraction (XRD) 69 3.3 X-ray Photoelectron Spectroscopy (XPS) 72 3.4 Field Emission Scanning Electron Microscopy (FESEM) 74 3.5 Transmission Electron Microscopy (TEM) 76 3.6 Energy-Dispersive X-ray Spectroscopy (EDS) 79 3.7 Thermogravimetric Analysis (TGA) 81 3.8 Ultraviolet–Visible–Near-Infrared (UV–Vis–NIR) Absorption Spectroscopy 82 3.9 Dynamic Light Scattering (DLS) 84 3.10 Photoluminescence (PL) Study 85 3.11 Pump Power-Dependent UC 87 3.12 Recognition of Emission Color and Colorimetric Theory 88 Acknowledgment 89 References 89 4 Raman and FTIR Spectroscopic Techniques and Their Applications 97 Saurav K. Ojha and Animesh K. Ojha 4.1 Raman Spectroscopy 97 4.2 Fourier Transform Infrared (FTIR) Spectroscopy 99 4.2.1 FTIR in Transmission Mode 100 4.2.2 Attenuated Total Reflectance (ATR) 100 4.2.3 Diffuse Reflectance Infrared Fourier Transform Spectroscopy (drifts) 100 4.3 Applications of Raman Spectroscopy 100 4.3.1 Raman Study of Molecular Association in Hydrogen-Bonded Systems 100 4.3.2 Surface-Enhanced Raman Spectroscopy (SERS) 104 4.3.3 Resonance Raman Spectroscopy (RRS) 106 4.3.4 Raman Spectroscopy of Semiconducting, Superconducting, and Perovskite Materials 107 4.4 Applications of FTIR Spectroscopy 108 4.4.1 FTIR Spectroscopy of Semiconductor, Superconductor, Hazardous, and Perovskite Materials 108 4.5 Raman and FTIR Spectroscopy of Upconverting Nanoparticles 109 References 110 5 Fundamental Aspects of Upconverting Nanoparticles (UCNPs) Based on Their Properties 117 Sushil K. Ranjan, Sasank Pattnaik, Vishab Kesarwani, and Vineet Kumar Rai 5.1 Introduction 117 5.2 Elucidation of Dynamics of UCNPs on the Basis of Fluorescence Decay Times 120 5.2.1 General Understanding of Depopulation Processes and UC Decay 120 5.2.2 Differentiating the ESA and ETU Mechanism Based on the Decay Profile 121 5.2.3 Theoretical and Experimental Approach of Understanding the Factors Affecting Upconversion Decay 123 5.3 Measurement of Quantum Yield of UCNPs 131 5.3.1 Role of Quantum Yield in Upconversion 132 5.3.2 Optical Methods of Measuring Quantum Yield of Upconverting Nanoparticles (UCNPs) 133 5.3.2.1 Relative Method of Measuring Quantum Yield 133 5.3.2.2 Absolute Method of Measuring Quantum Yield 133 5.3.2.3 Measurement of Intrinsic Quantum Yield of Lanthanide-Based Materials Using Lifetimes 134 5.3.3 Some Other Methods of Determining Quantum Yield 134 5.3.3.1 Photo-acoustic Spectroscopy (PAS) 134 5.3.3.2 Thermal Lensing (TL) Method 135 References 135 6 Frequency Upconversion in UCNPs Containing Transition Metal Ions 141 Manisha Prasad and Vineet Kumar Rai 6.1 Introduction 141 6.2 Synthesis of Transition Metal Ion-Activated Luminescent Nanomaterials 143 6.3 Structural and Optical Characterizations 143 6.4 Frequency Upconversion and Its Various Mechanisms 144 6.5 Applications 144 6.6 Mechanism of Transition Metal Ions in Crystal Field 145 6.6.1 UC Mechanisms in Mn-Based System 146 6.6.2 UC Mechanisms in Mn 4+ - and Ti 2+ -Based Systems 151 6.6.3 UC Mechanisms in Cr 3+ -Based System 153 6.6.4 UC Mechanisms in the Fe 3+ -Based System 155 6.6.5 UC Mechanisms in Co 3+ - and Ni 2+ -Based System 157 6.6.6 UC Mechanisms in Cu 2+ -, Zn 2+ -, and Zr 4+ -Based System 158 6.6.7 UC Mechanisms in Nb 5+ -, Mo 3+ -, Ru-, and Ag + -Based System 160 6.6.8 UC Mechanisms in W 6+ - and Re 4+ -Based System 161 6.6.9 UC Mechanisms in Os 4+ - and Au-Based System 162 References 164 7 Frequency Upconversion in UCNPs Containing Rare-Earth Ions 171 Sasank Pattnaik and Vineet Kumar Rai 7.1 Introduction 171 7.2 Familiarization with the Spectroscopic Behavior of RE 3+ Ion-Doped UCNPs 173 7.2.1 Physics of Trivalent Rare-Earth Ions 173 7.2.1.1 UC Mechanisms in Yb 3+ - and Pr 3+ -Based Systems 174 7.2.1.2 UC Mechanisms in Er-Based Systems 175 7.2.1.3 UC Mechanisms in Ho-Based Systems 177 7.2.1.4 UC Mechanisms in Tm-Based Systems 179 7.2.1.5 UC Mechanisms in Nd-Based Systems 181 7.2.1.6 Tri-Doped Systems 181 7.2.2 Color Modulation in UCNPs 184 7.2.2.1 Role of Dopant Concentration and Combination of RE 3+ Ions in Color Modulation 184 7.2.2.2 Role of Host/Dopant Combination in Color Modulation 186 7.2.2.3 Controlling the Emission Color Through Phonon Effects 186 7.2.2.4 Tuning UC Emission Using FRET 188 7.2.3 Quenching Mechanisms in UCNPs 190 7.3 Routes to Enhance Upconversion Luminescence in Nanoparticles 190 7.3.1 Dye Sensitization Techniques 191 7.3.2 Concentration Quenching Minimization 192 7.3.2.1 Suppression of Surface-Related Quenching 192 7.3.2.2 Removal of Detrimental Cross-Relaxation 193 7.3.3 Confinement of Energy Migration 194 7.3.4 Other Techniques to Enhance Upconversion Emission 195 7.3.4.1 Crystal-Phase Modification 195 7.3.4.2 Constructing an Active Core/Active Shell Strategy 195 7.3.4.3 Conjugating Surface Plasmon Resonance Technique 195 7.3.4.4 Dielectric Superlensing-Mediated Strategy 196 7.4 Technological Applications 197 7.4.1 Photonic Applications 197 7.4.1.1 Light-Emitting Diodes (LEDs) 197 7.4.1.2 Photovoltaic Applications 198 7.4.2 Bioimaging 199 7.4.3 Photo-Induced Therapeutic Applications 200 7.4.3.1 Photodynamic Therapy 201 7.4.3.2 Photothermal Therapy 201 7.4.3.3 Photoactivated Chemotherapy (PACT) 202 7.4.4 Other Emerging Applications 203 7.4.4.1 Anticounterfeiting 203 7.4.4.2 Sensing and Detection 203 7.4.4.3 Optogenetic Stimulation 205 7.4.4.4 NIR Image Vision of Mammals 205 References 206 8 Smart Upconverting Nanoparticles and New Types of Upconverting Nanoparticles 221 Akhilesh K. Singh 8.1 Introduction 221 8.2 Upconverting Core–Shell Nanostructures 222 8.3 Hybrid Upconverting Nanoparticles 224 8.4 Magnetic Upconverting Nanoparticles 226 8.5 UC-Based Metal–Organic Frameworks 228 8.6 Smart UCNPs for Security Applications 230 8.7 Smart Upconverting Nanoparticles for Biological Applications 233 8.8 Smart Upconverting Nanoparticles for Sensing 235 8.9 Conclusion 236 References 237 9 Surface Modification and (Bio)Functionalization of Upconverting Nanoparticles 241 Yashashchandra Dwivedi 9.1 Introduction 241 9.2 Upconverting Nanomaterials 242 9.3 Surface Modification 245 9.4 Biofunctionalization of Upconverting Materials and Applications 247 References 257 10 Frequency Upconversion in Core@shell Nanoparticles 267 Raghumani S. Ningthoujam, Rashmi Joshi, and Manas Srivastava 10.1 Introduction 267 10.1.1 Downconversion 267 10.1.2 Upconversion 271 10.2 Synthesis of Core@shell and Core@shell@shell UCNPs 272 10.2.1 Thermolysis Method 272 10.2.2 Hot Injection 276 10.2.3 Cation Exchange 277 10.2.4 Structural Characterizations 277 10.2.5 Optical Characterization 281 10.2.5.1 Normal Conversion Process in Ln-Doped Core@shell Nanoparticles 283 10.2.5.2 Loop-Type and Avalanche-Type Upconversion Processes in Core@shell Nanoparticles 289 10.3 Frequency Upconversion and Its Various Mechanisms 291 10.3.1 Inorganic-Based Upconversion 291 10.4 Applications 297 10.4.1 Bioimaging Applications 297 10.4.1.1 Luminescence-Based Imaging 297 10.4.1.2 Other Imaging Probes (MRI, CT, and SPECT) 299 10.4.2 Photothermal Therapy (PTT) 301 10.4.3 Photodynamic Therapy (PDT) 303 10.4.4 Temperature Sensor 306 10.4.5 Security Ink 308 10.5 Conclusion 310 Acknowledgment 311 References 311 11 UCNPs in Solar, Forensic, Security Ink, and Anti-counterfeiting Applications 319 Kaushal Kumar, Neeraj Kumar Mishra, and Kumar Shwetabh 11.1 Introduction 319 11.2 UCNPs for Solar Cells 320 11.2.1 C-Si Solar Cells 321 11.2.2 Amorphous Silicon Solar Cells 323 11.2.3 GaAs-Based Solar Cells 324 11.2.4 Dye-Sensitized Solar Cells (DSSCs) 324 11.3 Forensic, Security Printing, and Anti-counterfeiting Applications 325 11.4 Biomedicals 331 11.4.1 Bioimaging 333 11.4.2 Biosensing 336 11.5 Display and Lighting Purposes 339 References 340 12 Application of Upconversion in Photocatalysis and Photodetectors 347 Priyam Singh, Sachin Singh, and Prabhakar Singh Sunil Kumar Singh 12.1 Introduction 347 12.2 Photocatalysis 349 12.3 Photodetector 357 12.4 Conclusion 365 References 365 13 UCNPs in Lighting and Displays 375 Riya Dey 13.1 Introduction 375 13.2 Major Factors that Affect the UC Emission Efficiency 375 13.3 UC Mechanisms with Rate Equations 378 13.3.1 Pump Power Dependence in the Case of Dominant ETU-Assisted Upconversion over ESA 379 13.3.2 Pump Power Dependence in the Case of Dominant ESA-Assisted Upconversion over ETU 380 13.4 UCNPs in Solid-State Laser 380 13.5 UCNPs in Solid-State Lighting and Displays 384 13.5.1 Requirements for LED Applications 384 References 388 14 Upconversion Nanoparticles in pH Sensing Applications 395 Manoj Kumar Mahata, Ranjit De, and Kang Taek Lee 14.1 Introduction 395 14.2 Basic Properties of UCNPs 397 14.3 Working Principle of UCNP-Based pH Sensor 400 14.4 Photon Upconversion-Based pH Sensing Systems 401 14.4.1 Upconversion Nanoparticles as pH Sensors 401 14.4.2 Upconversion-Based pH Sensing Membranes 405 14.5 Conclusion 410 References 411 15 Upconversion Nanoparticles in Temperature Sensing and Optical Heating Applications 417 Praveen K. Shahi and Shyam B. Rai 15.1 Introduction 417 15.2 Classification of Temperature Sensors: Primary and Secondary Thermometers 420 15.3 Performance of Temperature Sensors 420 15.3.1 Thermal Sensitivity 421 15.3.2 Thermal Uncertainty (δT) 421 15.3.3 Reproducibility and Repeatability 422 15.4 Temperature Sensing with Luminescence 423 15.4.1 Time-Integrated Schemes 424 15.4.1.1 Fluorescence Intensity Ratio (FIR) or Band Shape 424 15.4.1.2 Bandwidth 426 15.4.2 Lifetime Technique 427 15.5 Upconversion (UC) and UC-Based Thermal Sensor of Ln 3+ Ions 427 15.5.1 Upconversion (UC) and Upconverting Nanoparticles (UCNPs) 427 15.5.2 Single-Center UC Nanothermometers and Multicenter UC Nanothermometers 428 15.5.3 Complex Systems 430 15.6 Optical Heating 433 References 437 16 Upconverting Nanoparticles in Pollutant Degradation and Hydrogen Generation 449 Wanni Wang, Zhaoyou Chu, Benjin Chen, and Haisheng Qian 16.1 Introduction 449 16.2 Degradation of Organic Pollutants 450 16.2.1 Degradation of RhB 451 16.2.2 Degradation of MB 455 16.2.3 Degradation of MO 460 16.2.4 Degradation of Various Organic Pollutants 462 16.2.5 Others 467 16.3 Degradation of Inorganic Pollutants 469 16.4 Photocatalytic Hydrogen Production 473 16.5 Conclusion 481 References 481 17 Upconverting Nanoparticles in the Detection of Fungicides and Plant Viruses 493 Vishab Kesarwani and Vineet Kumar Rai 17.1 Introduction 493 17.2 Visual Detection of Fungicides 495 17.2.1 Detection Mechanisms 495 17.2.1.1 Forster Resonance Energy Transfer (FRET) 495 17.2.1.2 Inner Filter Effect (IFE) 496 17.2.1.3 Photoinduced Electron Transfer (PET) 499 17.2.1.4 Electron Exchange (EE) 500 17.2.2 Significant Works on Upconversion-Based Fungicide Detection 500 17.3 Detection of Plant Viruses 505 17.3.1 Plant Virus Detection/Management Strategies 505 17.3.1.1 Direct Interactions 505 17.3.1.2 Indirect Interactions 505 17.3.1.3 NPs as Biosensors for Virus Detection 507 17.3.1.4 RNAi Process for Antiviral Protection 507 17.3.2 Significant Works on Plant Virus Detection Based on UCNPs 507 17.4 Future Challenges Regarding NP-Based Fungicide and Plant Virus Detection 509 References 510 18 Upconversion Nanoparticles in Biological Applications 517 Poulami Mukherjee and Sumanta Kumar Sahu 18.1 Introduction 517 18.2 Upconversion Nanoparticles in Bioimaging 518 18.2.1 Cell Imaging 518 18.2.2 Multimodal Imaging 520 18.3 Upconversion Nanoparticles in Drug Delivery 522 18.3.1 Different Types of Surface Modification 524 18.3.1.1 Polymer Coating 524 18.3.1.2 Silica Coating 524 18.3.1.3 Metal Oxide-Coated UCNPs 525 18.3.1.4 Functionalization of UCNPs 525 18.3.1.5 Metal–Organic Framework Coating 525 18.3.2 Drug Release 526 18.3.2.1 NIR-Triggered Drug Delivery System 526 18.3.2.2 pH and Thermoresponsive Drug Release 526 18.4 Upconversion in Photodynamic Therapy 526 18.4.1 Surface Modification of UCNPs for PDT 529 18.5 Photothermal Therapy 531 References 533 Index 539

About the Author :
Vineet Kumar Rai is Professor of Physics at the Indian Institute of Technology at Dhanbad (India). Professor Rai holds a Ph.D. in Physics from Banaras Hindu University. His main interest is in the synthesis and optical characterization of lanthanides-activated advanced materials, including the upconversion spectroscopy of rare earth ions, advanced optical materials, and their applications.