Hybrid octa-silane polyhedral oligomeric silsesquioxane (OS-POSS) optical films prepared by ion beam assisted evaporation

Abstract

Ion beam assisted thermal evaporation of the octa-silane polyhedral oligomeric silsesquioxane solid organic precursor was employed to deposit hybrid silicon oxide for the first time. This deposition process was primarily developed for ophthalmic lens applications as an alternative to the ion beam assisted chemical vapor deposition process. The main advantage of the proposed concept combining thermal evaporation and ion beam discharge is its transferability to industrial systems without significant scale-up investments. In the first part of this work, we performed a detailed diagnostic analysis (residual gas analysis and optical emission spectroscopy) of the effect of the experimental parameters on gas-phase processes. In the second part, we assessed and discussed the optical, chemical, structural, and mechanical properties of the deposited films. It has been found that the discharge current and oxygen gas ratio are the main parameters that adjust the coating properties and performance over a broad range. The adequately optimized combination of these two parameters allows one to fabricate flexible optical films with a low refractive index and a high elastic recovery.