The Preparation Of BaTiO₃ Thin Film And Its Photoelectric Properties

Recently,with the rapid development of optoelectronic information technology,miniaturization and thinning of optoelectronic components have become a development trend and research hot spot for electronic components,and accordingly,manufacturing technology of high-performance optoelectronic films is receiving a lot of attention.Barium titanate(BaTiO₃,for short BTO)film has good physical and chemical stability,good photocatalyst,photoelectric reaction and dielectric properties,and is widely used in ceramic capacitors,BaTiO₃ films,and optoelectronic devices such as silicon or silicon nitride.The advantages of these thin film devices,such as integrated electro-optic modulators and biosensors,are high energy storage density,low driving voltage and high transmission speed.Currently,researchers focus on the preparation of the BTO film and optimize the process parameters to achieve the purpose of controlling the structure and photoelectric properties of the film.In this paper,to improve the performance of BTO film,we design and control the structure of BTO film based on the preparation of BTO film,and the main research work and results are as follows.(1)Barium titanate powder sintered barium titanate ceramic(relative density 99%)target was prepared by thermal water method using high frequency magnetron sputtering method to discuss the structure and structure of BTO film under various oxygen content structure control mechanisms.In terms of performance according to the law of influence,a BTO film with a sandwich structure of"poor oxygen+rich oxygen+poor oxygen"is constructed on the ITO substrate.The results show that the substrate heating temperature is350°C,the operating pressure is 1.6 Pa,and the sputtering power is 150 W.The thickness of the BTO film is 810 nm.The sandwich structure"poor oxygen+rich oxygen+poor oxygen"improves the crystallinity and particle size of barium titanate film and reduces dielectric loss.Compared with the BTO film prepared under pure oxygen concentration,the diffraction peak intensity ratio I₍₁₁₀₎/I₍₁₁₀₎is 1.23,and the visible light transmittance reaches55%.Prepared ITO/BTO/Ag film capacitor and obtained dielectric temperature spectrum through LCR test showed that the dielectric loss value at room temperature was 0.025 and dielectric constant was 3.1 when the film thickness was 810 nm.(2)Through the experiment,we confirmed the important effect of different oxygen content structures on the properties of BTO films,and then systematically studied the internal relationship between different film thicknesses and film properties.The results show that the intensity of the characteristic diffraction peak of the(110)crystal plane by XRD analysis increases as the film thickness increases,the crystallinity of the film thickness is better at 800 nm,and the surface porosity of the BTO film is indicated.In SEM analysis,the cross-sectional shape of the film is uniform and dense,and when the film thickness is 800nm,the average roughness value(Ra)is 6.89 nm,indicating that the crystallinity of the film is obtained.The average visible light transmittance is 55.4%,and the film thickness is 600nm.At this time,the transmittance was reduced by 3%compared to that and the corresponding optical band gap was 3.83 eV.The dielectric temperature spectrum obtained by the LCR test shows that the dielectric loss value is 0.015 and the dielectric constant value is 3.When the film thickness is 800 nm at room temperature.(3)BTO film with good crystallinity was prepared on a silica substrate by the sol-gel method,and the effects of different molar concentrations of BTO sol on the optical properties of the film were investigated.I studied it.Optimization experiment results:0.8 mol/L BTO sol was spin coated and annealed layer by layer 6 times to obtain a film with better crystallinity.XRD pattern analysis showed that the crystal state has more pronounced characteristic diffraction than amorphous film.give.peak.In the SEM surface topography,the crystal film has few pores,the film surface is relatively flat,and the average particle size reaches 160.5 nm.The transmittance of the crystalline BTO film is 47.5%,which is 24.5%lower than that of the amorphous BTO film,and the optical band gap(3.61 eV)of the amorphous film is larger than that of the crystalline film(3.25 eV).Set the final annealing temperature to 850?and the annealing time to 0.5 hours.Compared to the characteristic diffraction peak at 800?,the XRD characteristic diffraction peak was greatly improved at this temperature.The average particle size is calculated by Scherrer's formula,reaching180.21 nm,the average visible light transmittance is 37.6%,and the forbidden band of the film is 3.3 eV.