Polyurethanes as low cost and efficient encapsulant materials for (flexible) Perovskite Solar Cells

Long-term stability of Perovskite Solar Cells (PSCs) is the main issue to be solved for a forthcoming commercialization of this technology. The stability of PSCs mainly suffers for water and oxygen infiltration as well as prolonged exposition to UV radiation. Straightforwardly, encapsulation of devices is a mandatory to achieve good long-term stability. Up to now, best encapsulant properties have been reached by the employment of nanometric film of metal oxides deposited by ALD. Nevertheless, the latter approach inadequately fits the requirement of flexibility. Among the feasible matrixes to be used as encapsulant film, we resolved to polyurethanes (PU) that are polymers build up by the condensation between diisocyanate and polyol moieties.