Postpassivation of Multication Perovskite with Rubidium Butyrate

• DOI: 10.1021/acsphotonics.0c00878
• Publication Date: 2020-07-14T19:07:20Z
• Authors: José Carlos Germino; Rodrigo Szostak; Silvia G. Motti; Raphael F. Moral; Paulo E. Marchezi; Heitor S. Seleghini; Luiz G. Bonato; Francineide Lopes...; Teresa D. Z. Atvars; Laura M. Herz; David Fenning; Anders Hagfeldt; Ana Flávia Nogueira
• Keywords: Passivation; Formamidinium; Rubidium

Many multication perovskites for highly stable and efficient solar cells benefit from rubidium iodide introduced in the precursor solution. It is well-known that Rb+ influences positively optoelectronic mobility properties has a direct effect upon crystallization halide homogenization. As often incorporated by adding RbI solution, it can be difficult to distinguish influence of I– separately. Herein, we report postpassivation methylammonium-free (CsFA) perovskite films with butyrate (RbBu). The passivation RbBu increases hydrophobicity surface passivates shallow deep traps, leading an increase charge-carrier lifetimes diffusion lengths. Consequently, better photovoltaic performance also observed. These superior are attributed both (halide-vacancy) grain-boundary carboxylate group Rb+, respectively. We found itself acts as powerful passivating agent perovskites, this proven decoupling its contribution halide's other important parameters (e.g., crystallization, vacancies filling, etc.).