Self-cleaning SiOx-embedded TiO2/SiO2 alternating multilayer

Abstract

A new method of inserting an eco-sustainable hydrophilic system into an anti-reflection (AR) system was developed and its applicability to photovoltaic systems was determined. We created a TiO₂ nanoparticle composite with a densely multi-layered AR system top layer to demonstrate its eco-sustainable, hydrophilic performance and to act as a low refractive index material, which is essential for AR. The hydrophilic system displayed the lowest reflectance and a remarkable contact angle reduction to 0 degrees under UV light irradiation. The annealed hydrophilic system (the eco-sustainable system) exhibited the highest photodecomposition activity of 100% within 90 min by effective separation of electron–hole pairs using SiO_x nanoparticles inside the TiO₂ layer as trap levels. The successful AR, hydrophilic, and eco-sustainable characteristics of the simplified system composed of only two materials, TiO₂ and SiO_x, are anticipated to contribute to the enhancement of photovoltaic system efficiency.