Polymers and photopolymers engineering to achieve unconventional properties in solar cells and smart windows

Photovoltaic (PV) technology has evolved rapidly in the past few decades and now encompasses a large variety of materials and device structures. A key aspect to be taken into account in any PV technology is the operational durability of these systems in outdoor conditions. In this context, the large compositional flexibility of polymeric materials as well as their proven easy processability may be of great help. The first part of this contribution shows a series of photocurable fluoropolymeric systems that find application as multifunctional coatings for different solution-processable PV devices, including perovskite solar cells and photoelectrochromic windows. Aspects related to the chemical functionalization of the coating precursors will be addressed in view of the incorporation of multiple functionalities into the final coating material, such as high photochemical durability, luminescent down-shifting, UV-screening, high hydrophobicity and easy-cleanability. It will also be demonstrated that by synthetically tuning the functionality of the coating system, improved power conversion efficiency and unmatched long-term operational stability can be achieved on all PV systems investigated. In the second part of this contribution, patterned “Fakir”-shaped super-hydrophobic polymeric architecture on the external sided of flexible solar cells are demonstrated to pave the way to floating PV devices. This represents and emerging trend in the PV scenario, with the ambitious aim to avoid not only the overheating of cells and water evaporation from water bodies in the driest areas, but also the installation of photovoltaic systems on land, thus reserving land use for agriculture or building.