Evaluation of Ethylene-Vinyl Acetate, Methyl Methacrylate, and Polyvinylidene Fluoride as Encapsulating Materials for Perovskite-Based Solar Cells, Using the Low-Temperature Encapsulation Method in a Cleanroom Environment

In this article, the development of a stable perovskite-based photovoltaic device manufactured in a controlled environment, with humidity between 40 and 65%, and encapsulated is presented. Encapsulation using polymers like ethylene-vinyl acetate (EVA), polymethyl methacrylate (PMMA), and EVA combined with polyvinylidene fluoride (PVDF) was proposed due to the low curing temperatures, insulating properties, and simple deposition processes of these materials. Testing involved subjecting these materials to humidity, temperature, and UV irradiation, following the International Summit on Stability of Organic Photovoltaics (ISOS-T) protocols, and using a 24 W UV lamp. Characterization analyses were carried out using various technologies including digital microscopy, spectroscopic ellipsometry, Fourier-transform infrared spectroscopy and electrical simulations. The results indicate that EVA-encapsulated samples displayed higher stability and resistance against external factors compared to PMMA and EVA-PVDF. Specifically, the EVA-encapsulated samples maintained a 15.06% power conversion efficiency (PCE) after the thermal cycles were carried out, reducing only by 0.9% compared to pristine samples. Similarly, after 350 h of UV exposure, they retained a PCE of 13.90%, decreasing by just 9.58% compared to the initial value.