The Study Of Synthesis And Optical Properties Of Metal Halide Perovskite

Recently,owing to the excellent optoelectric properties,for example,high absorption coefficient,long carrier diffusion length,high tolerance of defect states and bipolar carrier transport property,metal halide perovskites have broad prospects in the field of optoelectric devices.It is of great scientific significance to study the synthesis and photo-physical properties of micro/nano structures of metal halides for the development of high-performance photonic devices.In this thesis,we systematically studied the growth and luminescence mechanism of metal halide nanowires/platelets on mica surface by utilizing chemical vapor deposition method and laser spectroscopy measurement.The major results are:?1??Exploring the exciton-phonon interaction of cesium lead bromide?CsPbBr₃?perovskite nanowires?NWs?is not only important to the fundamental understanding of phonon-assisted carrier dynamics but also critical for the development of high performance miniaturized light sources.We systematically investigated the temperature?T?dependent spontaneous emission?SE?and lasing spectra of chemical vapor deposited CsPbBr₃ NWs,the results demonstrate that the synergistic effect of lattice thermal expansion?TE?and electron-phonon?EP?coupling is the main factor in affecting light emission.The lattice TE effect plays a key role at T?78-170 K,therefore both lasing and SE peaks exhibit a nearly linear blueshift with increasing T.As T>195 K,the EP interaction becomes dominate,which reduces the blueshift rate of SE peak and causes an inverse redshift of lasing peaks.?2??Lead Iodide?PbI₂?is a layered semiconductor with direct band gap holding great promises in green light emission and detection devices.Meanwhile,PbI₂ is a precursor of lead halide perovskites which have recently attracted great attentions in low threshold lasers.In this work,Fabry-Pérot?F-P?mode lasing was realized in trapezoidal PbI₂ nanoplatelets?NPs?and the threshold is at least an order of magnitude lower than the previous value is reported.Furthermore,the growth mechanism of the trapezoidal NPs is explored and attributed to the synergistic effects of van der Waals interactions and lattice mismatching.The findings not only advance the understanding of growth and photo-physics mechanism of PbI₂ nanostructures but also provide ideas to develop low threshold ultrathin lasers.