Postpassivation of Multication Perovskite with Rubidium Butyrate

Author(s):Show less -

Germino, Jose Carlos ^[1] ; Szostak, Rodrigo ^{[1, 2]} ; Motti, Silvia G. ^[3] ; Moral, Raphael F. ^[1] ; Marchezi, Paulo E. ^[1] ; Seleghini, Heitor S. ^[1] ; Bonato, Luiz G. ^[1] ; de Araujo, Francineide Lopes ^[1] ; Atvars, Teresa D. Z. ^[1] ; Herz, Laura M. ^[3] ; Fenning, David ^[4] ; Hagfeldt, Anders ^[2] ; Nogueira, Ana Flavia ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Lab Nanotecnol & Energia Solar, Inst Chem, BR-13083970 Campinas - Brazil

^[2] Ecole Polytech Fed Lausanne, Lab Photomol Sci, Inst Chem Sci & Engn, CH-1015 Lausanne - Switzerland

^[3] Univ Oxford, Dept Phys, Oxford OX1 3PU - England

^[4] Univ Calif San Diego, Dept Nanoengn, La Jolla, CA 92093 - USA

• Document type: Journal article
• Source: ACS PHOTONICS; v. 7, n. 8, p. 2282-2291, AUG 19 2020.
• Web of Science Citations: 3

Abstract

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

• FAPESP's process: 18/25801-0 - Preparation of the highly efficient perovskite solar cells through the compressed air gas quenching method and lead replacement by barium
• Grantee: Rodrigo Szostak
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Research Grants - Applied Research Centers Program
• FAPESP's process: 19/25765-6 - In situ experiments with synchrotron based SAXS and WAXS to probe reactions and formation mechanisms of trending (nanostructured) lead halide materials
• Grantee: Raphael Fernando Moral
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/12582-5 - Perovskites with mixed cations: Relationship between structure, composition, electronic properties and efficiency of solar cells
• Grantee: Rodrigo Szostak
• Support Opportunities: Scholarships in Brazil - Doctorate