Study Of Strain Adjustable Microtube With Coupled Quantum Well

In recent years,due to its unique physical properties,the micro-nano structure has become the focus of current research and has been widely used in the fields of optics,sensing,micro-drive,energy storage and so on.The common micro-nano structure has the following kinds: tube structure,fold-like structure,chain-like structure,ring structure and so on.There are a variety of methods for preparing these micro-nano structures,the preparation method based on rolled-up nanotechnology is widely used,which combines the Top-down method and the Bottom-up method to carry out nanomembrane growth and nanomembrane etching,and then roll the nanomembrane with internal stress from the substrate to prepare the three-dimensional micro-nano structure with controllable shape.Because of the internal stress,the physical properties of the micro-nano structure will change.Therefore,in this paper,the three-dimensional microtubes containing coupled quantum wells are prepared by rolled-up nanotechnology.The relationship between the stress and the effect of strain on other properties is studied by means of theoretical and experimental methods,the specific work is as follows:1.In the theoretical part,we understand the preparation mechanism of the coupling quantum well nanomembrane by studying the traditional nanomaterials,structure and rolling direction;Through the study of material growth and sample preparation method,we know the basic process of preparing nanomembrane;After mastering these concepts,strain release and electron transition in the system are analyzed by linear strain theory and electron band theory.2.On the basis of previous experiments,the designed thin nanomembrane were made into microtubes,the traditional lithography and chemical wet etching process are used to process patterned nanomembrane and selectively corrode sacrificial layers,so that the nanomembrane can be rolled up into microtubes.After testing the photoluminescence spectra of the prepared microtubes,we can get the final strain release of microtubes.3.Strain is influenced by external conditions,therefore,based on theoretical knowledge and experimental process,We further explore the influence of external conditions-the change of corrosion fluid concentration on the strain and optical properties of the system.After the measurement of the photoluminescence of the prepared micro-tubes,it is found that there are two kinds of strain release in different samples,which show the different release of axial stress,and the photo-luminescence spectrum shows the movement of peak position.The results of different concentrations of HF etching samples show that the uniaxial strain release and biaxial strain release of the micro-tube are not only related to the influence of the substrate on the micro-tube,but also related to the starting state of the micro-tube rolling,and the two strains can be converted to each other under certain conditions.The adjustment of etching solution changed the release of strain in the micro-tube,the function of the quantum well is expressed as the change of the energy gap,can be corresponded by photoluminescence technology of the quantum well in the transition peak position of the exciton,compared with the theoretical values can be determined in the micro-tube strain release type,so as to accurately regulate the final micro/nano system strain state.