Comparison of Glass–Glass versus Glass–Backsheet Encapsulation Applied to Carbon-Based Perovskite Solar Cells

The record photovoltaic performance of perovskite solar cells is constantly increasing, reaching 26% currently. However, there is a crucial need for the development of simple architectures that are compatible with large-scale industrialization and possess adequate stability. The aim of the work presented here is to compare the efficiency of glass–glass and glass–backsheet encapsulations for carbon-based perovskite solar cell application, which possesses a great potential for industrialization. This was conducted by first separating the relative effects of humidity and heat. A time evolution of the macroscopic power conversion efficiency (PCE) was performed, together with specific characterizations in order to scout the origin of flaws and degradations. A significant contribution of the paper is the identification of both TiO<inf>2</inf> and carbon layers as barriers against moisture permeation, which inhibit moisture paths through the interfaces. This is the origin of the equivalent durability of both studied systems, even if the glass–backsheet encapsulation was found to be less efficient than the glass–glass encapsulation at protecting perovskite from damp-heat aging when TiO<inf>2</inf> or carbon layers are not used.