Research On Preparation And Spectroscopic Of In Doped SnO₂, ZnO And SnO₂/ZnO Hetero-structure

Doping and heterostructure can regulate the physical and chemical properties ofnanomaterial, it has extensive application prospects in the field of manufacture ofsemiconductor optical device, electronic device, sensor and so on. This article usesmany methods to successfully prepare the In-doped SnO₂nanoparticle, In-doped ZnOhexagonal nanosheet and SnO₂/ZnO core-shell nanowire. With the help of XRD, SEM,TEM and spectrum analyzer the characterization to material microstructure. With thehelp of Raman, PL and UV-vis, we study and discussion the optical properties ofmaterials.1、In-doped SnO₂nanoparticlesIt is the first time to use hydrothermal method to successfully compose theIn-doped SnO₂nanoparticle. The analysis result of XRD showed that In-doped SnO₂nanoparticles led to the lattice change of SnO₂nanoparticles, resulting diffractionpeak position deflect to the2θ larger degree. TEM characterization result showed thatthe diameter of SnO₂nanoparticles is3-5nm, the （110） crystal plane of correspondinglattice spacing is3.345nm. The analysis result of UV-vis and PL spectrum showed thatdoping makes SnO₂nanoparticles to produce more defects and oxygen vacancies, theadditional energy level produced by defects between the valence band and conductionband led to SnO₂bandgap broaden. With the conclusion of XRD, UV and spectrumanalysis, we can get a result that1.9%concentration of doping do greatest impact toXRD diffraction peak center of SnO₂,bandgap and PL spectrum deconvolution position.By comparing to the analysis and optical properties of different concentration SnO₂nanoparticles,1.9%concentration of doping can control well to SnO₂properties.2、In-doped ZnO hexagonal nanosheetsIt is the first time to use hydrothermal synthesis method to prepare the In-dopedZnO hexagonal nanosheets. SAED, TEM snalysis result showed that ZnO naronod issingle crystal structure, nanorod grows along with [0001] crystal direction, the latticespacing is0.260nm, In-doped suppress the preferential growth of ZnO direction, turnto [1010]、[1100]、[0110]、[1010]、[1100]、[0110]six equicvalent direction of rapidgrowth and form hexagonal laminar structure. The test for In-doped ZnO nanosheetsbandgap of UV-vis absorption spectrum is2.94eV. Photoluminescence spectrumobversed that because of doping of in element, ZnO nanosheets band edge emissiondisappeared, and it existed a wide and high strength defect luminous zone between 450nm-700nm.3、SnO₂/ZnO core-shell nanowiresSnO₂/ZnO core-shell nanowiress were successeful prepared by two-stepssynthesized. The first step is using low vacuum thermal evaporation method to preparethe ultrafine SnO₂nanowires with diameter of50nm, the surface of nanowire is smoothand grows along with [200] direction. Based on the preparation of SnO₂nanowires,using the thermal decomposition method of zinc acetate solution coats layer on thegrowth surface of SnO₂nanowires. The study showed that in the constantdecomposition temperature, the concentration of zinc acetate solution magnifies, andthe thickness of ZnO coating layer increases. The bandgap of SnO₂nanowires withUV-vis absorption spectrum measurement is3.74eV, the bandgap of SnO₂/ZnOcore-shell structure is3.20eV. With the influence of heterostructure, the bandgap ofmaterial narrows down. The PL spectroscopy SnO₂/ZnO core-shell structure appearsthe emission peak in394.4nm（3.14eV）、520.7nm（2.38eV）、571.5nm（2.17eV） and597.4nm（2.08eV）. The emission peak of394.4nm is caused by the radiation of excitonlevel electronic transition back to the valence band. And the emission peak of520.7nm、571.5nm and597.4nm relates to the oxygen vacancy and surface defect.