Study On The SiO₂ Antireflective Coatings Prepared From Sol-Gel Process

Anti-reflective coatings (AR coating) play an important role in modern times optical film production, which has been studied in detail during the past decades. Now, there are many kinds of AR coatings in use which can satisfy the need of technical optics. In high power laser system, the reflection of instrument must be farthing, or the sense organ will be destroyed. So such film is difficult to prepare, and requirement urges its progress. In recent years, a method called sol-gel coating developed quickly. This method does not have the above-mentioned shortages, and its preparation techniques is so simple, operational temperature is lower.In this paper, we studied in detail the effect of acid and alkaline catalysts on film capability, and discussed the effect of the ammonia, water and solvent dosage. We review the course of the hydrolyzation and polycondensation of TEOS, by tracking the reflective index and turbidity. It's found that the surface morphologies and performance of the films is different when using different catalysts, because the cluster structure is different. With the increasing of water, the time of sol be preserved stably is prolonged. Solvent also has effect on the hydrolyzation of TEOS and the volatilization of gel, what will determine the structure of films on certain extent. It's also found that the antireflective effect of the film is optimal while the reflective index of the sol is lowest, and the peak transmission of coatings are about 99.45%.