Controllable Synthesis And Optical Properties Of Indium Micro And Nanostructures

Indium has low melting point,good flexibility and excellent photoelectric performance.Its micro and nanostructure has important application prospects in flexible micro and nano optoelectronic devices,vacuum micro and nano seal,microfluidic thermal conductivity and conductive ink.Meanwhile,indium atom has three valence electrons,so indium nanoparticles have significant surface plasmons from deep ultraviolet to visible light region,which has important application value in biochemical analysis and photoelectric information amplification and enhancement.In this dissertation,large area single crystal indium microslices were synthesized in organic solvent by wet chemical method.Then,the size and morphology of various micro and nanostructures of indium are controlled effectively.Finally,the regulation of surface plasmons of indium nanoparticles was studied and its application was explored.Specific research contents and results are as follows:（1）Single crystal indium microslices were successfully synthesized in organic solvent by one-step synthetic wet chemistry method and subsequent cooling method.Its average length is about 20μm and width is about 2.5μm,and its yield is high.The results show that single crystal indium microslices have good crystal orientation growth.Further studies shows that the growth of indium microslices was divided into two steps:the first step was to form indium nanoparticles after reduction by Na BH₄.In the second step,the single crystal particles are oriented and bonded to grow into single crystal indium microchips in the process of water cooling.（2）Then,the size and morphology of indium micro and nano structures were comprehensively and deeply controlled from five aspects.By changing the cooling rate,the synthesis temperature,the relative content of reducing agent,the amount of solvent and the amount of tin doping,the size and morphology of the micro and nano structure were studied.The effective control methods and the best experimental conditions were obtained.The results are as follows:Firstly,indium nanoparticles,microwires,microbelts and microslices were obtained in different cooling media.Secondly,larger polygon indium slices can be produced at room temperature.Thirdly,when other conditions remain unchanged,the size,morphology and yield of the product can be controlled only by changing the amount of solvent.when the ratio of BH₄^-to In³⁺is 2,the indium micro slics with good quality and high yield can be synthesized.Fifthly,tin doping can form indium tin alloy microslices,but excessive tin element inhibits the growth of indium microslices.（3）Finally,The indium nanoparticles were prepared by one-step wet chemical method.By changing the relative content of reducing agent and synthesis temperature,the surface plasmon was adjusted from deep ultraviolet to visible light.Finally,the fluorescence and Raman enhancement effects of indium nanoparticles and their composite structures are preliminarily discussed.The results show that the composite structure of indium nanoparticles and microslices has stronger optical enhancement effect than single particle.In this study,large-area single crystal indium microchips were synthesized in solvent,and the size and morphology of indium micro nano structure were efficiently controlled,and the surface plasmon of indium nanoparticles were adjusted from deep ultraviolet region to visible region.This dissertation will provide an important reference for the research of indium micro and nano single crystal growth.The indium micro and nano structural materials will have important application prospects in the fields of flexible optoelectronic devices,microfluidic thermal conductivity,conductive ink,vacuum micro and nano sealing,micro and nano welding,biochemical analysis and photoelectric information enhancement.