Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells

• DOI: 10.1021/jacs.0c08592
• Publication Date: 2020-11-10T20:25:53Z
• Authors: Tzu-Sen Su; Felix Thomas Eick...; Michael A. Hope; Farzaneh Jahanbak...; Marko Mladenović; Jun Li; Zhiwen Zhou; Aditya Mishra; Jun-Ho Yum; Dan Ren; Anurag Krishna; Olivier Ouellette; Tzu-Chien Wei; Hua Zhou; Hsin-Hsiang Huang; Mounir Driss Mensi; Kevin Sivula; Shaik M. Zakeeruddin; Jovana V. Milić; Anders Hagfeldt; Ursula Rothlisberger; Lyndon Emsley; Hong Zhang; Michael Grätzel
• Keywords: density; Chemical Sciences not elsewhere classified; perovskite films; undercoordinated surface defects; Cell Biology; stability; 01 natural sciences; 7. Clean energy; 0104 chemical sciences; power conversion efficiencies; Space Science; Environmental Sciences not elsewhere classified; Medicine; crown ether hosts; crown Ether Modulation Enables; photovoltaic performance; perovskite-based optoelectronic devices; Biological Sciences not elsewhere classified

The use of molecular modulators to reduce the defect density at the surface and grain boundaries of perovskite materials has been demonstrated to be an effective approach to enhance the photovoltaic performance and device stability of perovskite solar cells. Herein, we employ crown ethers to modulate perovskite films, affording passivation of undercoordinated surface defects. This interaction has been elucidated by solid-state nuclear magnetic resonance and density functional theory calculations. The crown ether hosts induce the formation of host-guest complexes on the surface of the perovskite films, which reduces the concentration of surface electronic defects and suppresses nonradiative recombination by 40%, while minimizing moisture permeation. As a result, we achieved substantially improved photovoltaic performance with power conversion efficiencies exceeding 23%, accompanied by enhanced stability under ambient and operational conditions. This work opens a new avenue to improve the performance and stability of perovskite-based optoelectronic devices through supramolecular chemistry.