Organic/Inorganic Hybrid Moisture Permeation Barrier Films for Back-sheet of Silicon Photovoltaic Modules

s In the crystalline silicon-based photovoltaic system, Si solar cells are connected in series and high voltage larger than 1000 V is applied between module frames and cells during the operation. This can generate a leakage current through the modules and the loss of efficiency and output power called potential-induced degradation (PID) occurs. When the c-Si solar cell module is exposed to a high-temperature, high-humidity environment, water molecules penetrates through the back sheet of the module and EVA is corroded, which accelerates PID. Various methods to prevent the permeation of water molecules have been widely investigated. Here we propose organic/inorganic hybrid coatings that can provide high mechanical flexibility as well as low water vapor transmission rate (WVTR). Silamer, a Silane-based inorganic / organic hybrid polymer, flattens the surface of the commercial back sheet and Al2O3 grown on top of it suppresses the moisture permeation. Additional coating of the organic layer on Al2O3 shows the lowest WVTR of 0.36.