Desenvolvimento de células solares baseados em filmes fino de perovskita de iodeto de chumbo e metilamônio

Abstract

Perovskite-based solar cells have made impressive strides in recent years, surpassing 26% power conversion efficiency. In the context of solar cells based on methylammonium lead iodide (MAPbI3) perovskite films, this high efficiency is counterbalanced by its low environmental stability, being one of the main challenges of this technology. In the search for higher quality and resistance to environmental conditions of MAPbI3 films, the addition of carbon allotropes has proven to be a promising alternative. For these reasons, the proposal here was the development of solar cells based on MAPbI3 films modified by the incorporation of carbon quantum dots (CQDs) obtained from a peculiar fruit of the Amazon region. These CQDs were introduced into the MAPbI3 films by addition to the methylammonium iodide (MAI) precursor solution. The MAPbI3 material was synthesized by the two-step method. The introduction of CQDs was shown to positively influence the quality and stability of the MAPbI3 film, presenting suppression of the degradation mechanism for long hours under ambient conditions. Additionally, the grain size showed a significant reduction as the volume of CQDs was increased. The first signs of degradation were reported after 720h. Thus, these films allowed the fabrication of perovskite solar cells, based on MAPbI3, with improved efficiency that surpasses the reference device, managing to maintain more than 50% of its initial efficiency after 672h of aging under ambient atmosphere.