Recent trends on the application of phytochemical-based compounds as additives in the fabrication of perovskite solar cells

Abstract

Perovskite solar cells (PSCs) are promising photovoltaic systems that hold the capacity to bring about a paradigm shift within the field of renewable energy. They possess exceptional photophysical properties, and their advancement is accelerating because of multidimensional research initiatives. Nevertheless, PSCs are faced with the challenges of non-radiative recombination power losses and rapid degradation in performance. These problems are mainly engendered by defects that form during the perovskite crystallization. Among the many ways to address these issues are compositional engineering, architectural modification, control of deposition parameters, solvent engineering, doping, use of additives and interface engineering. Incorporating additives into the perovskite layer is an easy and effective approach to enhance both their photophysical characteristics and resistance to degradation. As PSC additives, natural products, including phytochemicals, are gaining popularity due to their low cost and environmental friendliness. This review provides a survey on the use of natural products as additives in PSCs with particular emphasis on phytochemicals. It also highlights the roles of phytochemical-based additives in modulating the optoelectronic and degradation resistance properties of perovskite films through control of the crystallization dynamics, defect passivation and structural stabilization. Focus has been given to the functional groups in these phytochemical-based additives and how they interact with the perovskite components through hydrogen-bonding, coordination with uncoordinated ionic/atomic species and scavenging of free radicals. Overall, the use of phytochemical-based additives could enhance the performance and stability of PSCs and accelerate their commercialization.