多孔性二氧化硅减反膜胶体规律性研究

Study on the Colloidal Regularityof Porous SiO_2 Antireflective Coatings

溶胶凝胶法制备减反膜在高功率激光装置中有着重要运用,通过控制水与正硅酸乙酯(TEOS)不同物质的量之比制备不同粒径大小的二氧化硅悬胶体及二氧化硅减反膜,可以研究悬胶体粒径大小对溶液及膜层的激光破坏阈值、光学减反效率稳定性影响。结果表明制备获得的多孔性SiO2减反膜透射率均高于99.5%,激光破坏阈值均大于62J/cm2(1064nm,15ns),其中粒径小的SiO2减反膜透射率达到99.75%,激光破坏阈值高达77.42J/cm2(1064nm,15ns)。随着水酯物质的量比值增大,悬胶体溶液平均粒径增大,当水酯物质的量比值大于3.5时粒径增大幅度加快;粒径在10nm以下的溶液具有优异的稳定性,溶液颗粒大小、粘度等性能基本保持不变。在不同湿度环境下研究不同粒径膜层的稳定性,所有膜层在高湿度环境中透射率有所下降,其中大粒径膜层下降更明显,化学膜更适合在湿度低的环境下使用。

Antireflective coatings prepared by sol gel method are importantly used in high power laser devices,the stability of colloidal,laser induced damage thresholds（LIDTs）and antireflective efficiencies of coatings resulted from different particle sizes silica colloidal suspensions and silica antireflective coatings are studied by controlling different molar ratios of water and tetraethoxysilane（TEOS）.The results show that the transmittance of porous silica antireflective films is higher than 99.5%and LIDTs are greater than 62 J/cm2（1064 nm,15 ns）,the transmittance and LIDTs of smaller particle size silica antireflective film reaches 99.75% and 77.42 J/cm2（1064 nm,15 ns）,respectively.The average particle sizes of colloidal suspensions increase with the mol ratio of H2O…TEOS,the particle size quickly increases when the molar ratio of water and ester is greater than 3.5.The solution with particle size below10 nm has excellent stability,and the particle size and viscosity of the solution is almost not unchanged.The stability of films with different particle sizes in different humidities is researched,all the films′transmittance in high humidity drops and the film with larger particle size has more obvious decrease in transmittance,and therefore the chemical films are more suitable for the use in low humidity environment.