Self-assembly of lead-halide-perovskite laser particles

Abstract

As profiling the molecular states of cellular subpopulations has become increasingly important to understand complex systems in biology and medicine, considerable efforts are being made to develop multiplexed techniques. While current fluorescent probes play indispensable roles, their broad emission spectra (about 30-100 nm) limit multiplexing capability. Recently, optical probes emitting narrowband laser spectra (about 0.1-1 nm), called 'laser particles', has drawn attention. Semiconductor microdisk lasers fabricated by top-down lithography have shown potential for massive multiplexing of thousands to millions of samples. In the thesis, I investigated lead halide perovskites (LHP) as a novel material for scalable production of laser particles in a lab flask. I discovered a sonochemical method to produce a large quantity (10 billions/L) of high-quality LHP micro- and sub-micron particles in a polar solvent within minutes. This method enabled me to coat the surface of individual CsPbBr3 laser particles using poly-catecholamine and thereby to improve optical properties and material stability against moisture. With CsPbBr3 microparticles coated with nano-scatterers, I realized disordered lasing based on Anderson localization. In addition, by incorporating plasmonic materials, I demonstrated plasmonic-lasing particles as small as 580 nm. This work paves the way for highly multiplexable laser particles for biomedical applications.