Description
This book highlights the rapidly emerging field of solution-processed halide perovskite lasers. These amazing materials not only possess exceptional photovoltaic properties, but are also outstanding optical gain media. Halide perovskites are the latest member of solution-processed optical gain media, joining organics and traditional semiconductor colloidal quantum dots. Amplified spontaneous emission and lasing have been demonstrated in various halide perovskite configurations and nanostructures with wavelengths tunable over the visible and infrared wavelengths (4001000 nm). This book provides comprehensive information on perovskite lasing, starting with some fundamentals of lasers and their basic operating principles. Unambiguous methods for identifying lasing light emission are presented, while the basic optoelectronic properties of perovskite materials are also discussed, with an emphasis on their photophysics, using ultrafast optical spectroscopy techniques. The viability of perovskites as a gain media within a suitable resonator, as well as the characterization methods for optical gain, are highlighted. The book closes with a discussion on the remaining challenges (such as electrical driven lasing and material stabilities) that need to be tackled, and the future of this new family of lasers. CHAPTER 1. Fundamentals of Lasers 1.1: What is a Laser? 1.2: Principles of Laser Operation 1.2.1: Resonators, Pump and Gain medium 1.2.2: Rate Equation Approach 1.3: Characteristics of Lasers 1.3.1: Modal Profiles 1.3.2: Spatial and Temporal Coherence 1.4: Types of Lasing 1.4.1: Fabry-Perot Lasing 1.4.2: Distributed Feedback Bragg (DFB) Lasing 1.4.3: Whispering Gallery Mode (WGM) Lasing 1.4.4: Random Lasing 1.5: How to recognize Lasing 1.5.1: Signatures of the Lasing emission 1.5.2: Look-alike Lasing Artefacts CHAPTER 2. Photophysics behind Perovskite Lasers 2.1: Introduction 2.1.1: The Perovskite Semiconductor 2.1.2: Basic Characterising Parameters of Perovskites 2.1.3: Exciton Bohr Radii and Quantum Confinement 2.2: Ultrafast Optical Spectroscopic Methods 2.2.1: Steady-state and Time-resolved Photoluminescence 2.2.2: Transient Absorption Spectroscopy 2.2.3: Angular Resolved Spectroscopy 2.3: Carrier Dynamics in the Perovskite Materials 2.3.1: Nature of Carriers: Exciton VS Free Electron-Holes 2.3.2: Band-edge Radiative Recombination 2.3.3: Interplay Between Radiative and Non-Radiative recombination Processes 2.3.4: Intraband Carrier Dynamics 2.3.5: Amplified Spontaneous Emission (ASE) 2.3.6: Material Quantum Yield of Fluorescence 2.3.7: Quenching Mechanisms of Light Amplification 2.4: Perovskite Photon Lasing 2.4.1: Parameters Relevant to Photon Lasing 2.4.2: Material Requirements 2.5: Perovskite Polariton Lasing 2.5.1: Parameters relevant to Polariton Lasing 2.5.2: Material Requirements 2.6: Summary and Conclusions CHAPTER 3. Perovskites as Viable Gain Media 3.1: Perovskite Materials in recent reports of Lasing 3.1.1: Perovskite Polycrystalline Thin Films 3.1.2: Perovskite Nanocrystals 3.1.3: Perovskite Nanoplatelets 3.1.4: Perovskite Nanowires 3.1.5: Perovskite Single Crystals 3.2: Optically Pumped Perovskite Lasing 3.2.1: Femtosecond Pulse Pumped Lasing 3.2.2: Nanosecond Pulse Pumped Lasing 3.2.3: Continuous Wave Pumped Lasing 3.2.4: Photostability of Perovskite Gain Materials 3.3: Summary and Conclusions CHAPTER 4. Fabricating Techniques of Practical Lasing Resonator 4.1: Fabrication Techniques of practical Lasing Resonators 4.1.1: Fabry-Perot: Vertical Cavity Surface Emitting Lasing (VCSEL) 4.1.2: Whispering Gallery Modes: Microcapillaries and Microspheres 4.1.3: Distributed Feedback Gratings 4.1.4: Highly Disordered Morphology for Random Lasing 4.2: Further Considerations in Optimisation of Lasing Cavity Designs 4.3 Summary and Conclusions CHAPTER 5. Conclusion 5.1: Challenges with Perovskite lasers 5.1.1: Toxicity Issue 5.1.2: Thermal Management Issue 5.1.3: Extending the photostability lifetime 5.1.4: Increasing the pump-generated Carrier Densities 5.1.5: Electrically Pumped Perovskite Lasing 5.2: Summary and Outlook
