Preparation And Study Of Doped Silicon Nanotubes

One-dimensional nanomaterials have excellent quantum tunneling effect,coulomb blocking effect,special electrical and optical properties.Silicon nanotubes（SiNTs）are a new type of semiconductor photoelectric materials with quantum confinement effect and small size effect,which may have both the performance of silicon nanowires（SiNWs）and carbon nanotubes（CNTs）,exhibit a large number of physical and chemical properties different from bulk materials,and can be compatible with current silicon chip technology.These properties make SiNTs promising lithium-ion batteries,nanoelectronic devices,nanodrug delivery,transistors,sensors,nanomagnetic devices,quantum computers,hydrogen storage,field emission display devices and optoelectronic devices and other fields of great potential,providing a new silicon nanomaterial in addition to CNTs and SiNWs for the future fabrication of nanoscale microdevices.Although the successful preparation of SiNTs solves the problem that has been predicted by international theories but has not been synthesized experimentally,the various properties of SiNTs,especially their doping properties,have not been fully studied,and the experiments and explorations of boron（B）and phosphorus（P）doped SiNTs have not been reported.In this paper,non-toxic and environmentally pollution-free silica（SiO₂）and silicon（Si）were used as silicon sources,and non-toxic boron trioxide（B₂O₃）and red phosphorus（P）were used as doping sources under the catalysis of the rare earth element lanthanum（La）to doping SiNTs.Firstly,the intrinsic SiNTs were prepared by thermal evaporation,and the experimental conditions suitable for the preparation of SiNTs were explored.Secondly,B and P were doped with intrinsic SiNTs,and doped SiNTs with controllable doping concentration and performance were explored under better experimental conditions and doping amounts.Specifically,multiple sets of experiments were carried out by changing the dosage of doping sources B₂O₃and P and the experimental temperature during the experiment.Finally,the samples are characterized by various equipment,and then the experimental conditions are fed back,so as to further improve the experimental process and study the various properties of SiNTs doped with B and P.If calculated based on the measurement of Raman spectra,it is expected that information on the total doping concentration can be obtained;Its structure was studied by scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,selective electron diffraction analysis（SAED）,energy spectroscopy（EDS）,X-ray diffraction analysis（XRD）,etc.Photoluminescence（PL）spectroscopy,etc.study optical properties.Through the characterization of experimental samples,it was found that SiNTs could be prepared by thermal evaporation under experimental conditions of 1280°C when 2.2 g SiO₂,1.4 g Siand 0.1 g La were used as the starting materials for the experiment.When a small amount of B₂O₃（0.1-0.4 g）was used and the experimental temperature was 1280°C,B-doped SiNTs could be generated.The addition of a small amount of B₂O₃is conducive to the formation of lines/tubes,and the number of products generated is,from less to most:No added B₂O₃<0.1 g B₂O₃<0.2 g B₂O₃<0.3 g B₂O₃<0.4 g B₂O₃;When the amount of B₂O₃used is large（2.2 g）and the experimental temperature is 1280°C,a"needle"structure material is generated.When the experimental temperature was higher than 1280°C,no B-doped SiNWs nor B-doped SiNTs were generated,regardless of the amount of B₂O₃doped.When P was used as the doping source,the experimental temperature was 1400°C and the dosage was 0.4 g,a new material was discovered that had not been previously reported.This new material has a special structure,into a"tube"-like double-shell structure,and HRTEM is observed to have darker"spots"on its tube body and small protrusions on both sides of the tube.At other temperatures and P dosages,only sheet structure material is generated.At the end of the paper,I put forward my views on how to improve the research of SiNTs,and through the doping preparation of SiNTs and their research,I hope to help SiNTs in future research and application.