Preparation And Thermal Stability Of Ti-doped Ag/TiO₂ Composite Films

Ag/TiO₂ composite film has good spectral selectivity.It is widely used in construction,automotive,home appliances and other fields.However,Ag element prone to have oxidation and agglomeration phenomenon in the high temperature environment resulting in reduced performance of composite film.In this paper,Ag/TiO₂ composite films doped with Ti were prepared by magnetron sputtering.It detected and characterized by UV-Vis spectrophotometer,field emission scanning electron microscopy（FESEM）,atomic force microscope（AFM）,X-ray diffraction（XRD）,spectrometer and heat insulation experiment device.The effects of Ti doping amount and heat treatment temperature on the microstructure and application properties of the composite films were systematically studied.1、The effects of doped Ti elements on the microstructure and transmittance of Ag/TiO₂ composite films were investigated.Results show that as the doping amount of Ti element increases from 1.6 at% to 16.2at%,the surface quality of Ag-Ti/TiO₂ composite films gradually increased and stabilized,The Ag crystallization quality and lighttransmitting and thermal insulation properties of Ag-Ti composite films showed the trend of increasing first and then decreasing.When the Ti doping content is 3.0 at%,the surface of the composite film has the best flatness and tissue compactness,the Ag（111）diffraction peak is the strongest,the crystal quality of silver is the best,the visible light transmittance reaches the maximum 78.6%,the insulation temperature reached a maximum of 5.5 ℃.2、The effects of heat treatment temperature on the microstructure and transparent insulation of Ag/TiO₂ composite films were investigated.Results show that with the heat treatment temperature rising from 25℃ to500℃,the surface of the composite film shows that the particle size increases from large to small and then increases,and the microstructure of the composite film increases first and then decreases.The microstructure is the intensity of the diffraction peak of Ag（111）firstly enhanced and then weakened and the intensity of the diffraction peak of Ag（200）is increasing.While the light transmission and thermal insulation performance showed that the average penetration of visible light increased first and then increased and then increased,the temperature difference of the insulation increases first and then decreases.When the heat treatment temperature is 200℃,the surface quality of the composite membrane is the best and transparent insulation performance is the best（the transmittance is 64.2%,the insulation temperature is 5.6℃）.When the heat treatment temperature is 500℃,the surface of the composite film is destroyed and the spectral selectivity is lost.3、The effects of heat treatment temperature on the microstructure and transparent insulation of Ag/TiO₂ composite films doped with 3.0at%Ti were investigated.Results showed that with the heat treatment temperature rising from 25℃ to 650℃,the diffraction peaks of Ag（111）and Ag（200）planes of Ag-Ti（3.0 at%）/TiO₂ composite films are gradually enhanced,surface quality and thermal insulation performance of the firstly rise and fall after the decline in the trend.When the heat treatment temperature is 400℃,the composite film has the highest surface quality and the best heat preservation performance（visible light average transmittance and thermal insulation temperature reached a maximum of73.6% and 6.5℃）.When the heat treatment temperature is 650℃,the surface of the film is agglomerated,and the spectral selectivity of the large area pores and falled off and its spectral selectivity is reduced.