Effectiveness of poly(methyl methacrylate) spray encapsulation for perovskite solar cells

Abstract

For commercial applications, Perovskite Solar Cells (PSCs) need to be well encapsulated to improve long term stability. The most common method, glass-glass encapsulation, uses edge sealant materials to encapsulate the device between sheets of glass. Glass-Glass encapsulation, while providing provide adequate protection from the ambient environment, limits the use of flexible substrates for thin film solar cells due to its rigidity. Additionally, the added weight of glass encapsulation reduces the specific power (W kg−1) of PSCs, which is an important factor when designing solar cells for aerospace applications. Here we demonstrate that commercially available acrylic spray encapsulation offers efficient and robust stability for PSCs. It is shown that applying the encapsulation via this method does not degrade the PSCs, unlike other literature and glass-glass encapsulation methods. Additionaly, it is shown that 1 coat of acrylic spray encapsulation has an effective thickness of ∼1.77 µm and a weight of ∼6 mg. For stability measurements, PSCs with an acrylic coating show a 4% increase in performance after ∼730 h under dark storage conditions and retain 88% of their initial power conversion efficiency after 288 h under 85% relative humidity 25 °C. We anticipate our assay to be a starting point for further studies into spray encapsulation materials and methods not just for terrestial applications, but for aerospace applications as well.