Chlorophyll Derivative-Sensitized TiO2 Electron Transport Layer for Record Efficiency of Cs2AgBiBr6 Double Perovskite Solar Cells

Baoning Wang; Na Li; Lin Yang; Chunxiang Dall'Agnese; Ajay Kumar Jena; Shin-Ichi Sasaki; Tsutomu Miyasaka; Hitoshi Tamiaki; Xiao-Feng Wang

doi:10.1021/jacs.0c12786

Chlorophyll Derivative-Sensitized TiO₂ Electron Transport Layer for Record Efficiency of Cs₂AgBiBr₆ Double Perovskite Solar Cells

J Am Chem Soc. 2021 Feb 10;143(5):2207-2211. doi: 10.1021/jacs.0c12786. Epub 2021 Feb 1.

Authors

Affiliations

¹ Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, China.
² Graduate School of Engineering, Toin University of Yokohama, Kanagawa 225-8503, Japan.
³ Graduate School of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
⁴ Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan.
⁵ Electron Microscopy Center, Jilin University, Changchun 130012, China.

PMID: 33522803
DOI: 10.1021/jacs.0c12786

Abstract

The power conversion efficiency (PCE) of Cs₂AgBiBr₆-based perovskite solar cells (PSCs) is still low owing to the inherent defects of Cs₂AgBiBr₆ films. Herein, we demonstrate a carboxy-chlorophyll derivative (C-Chl)-sensitized mesoporous TiO₂ (m-TiO₂) film as an electron transport layer (ETL) to enhance and extend the absorption spectrum of Cs₂AgBiBr₆-based PSCs. The C-Chl-based device achieves a significantly improved PCE, exceeding 3% for the first time, with an increase of 27% in short-circuit current density. Optoelectronic investigations confirm that the introduction of C-Chl reduces the defects, accelerates the electron extraction, and suppresses charge recombination at the interface of ETL/perovskite. Moreover, the unencapsulated PSCs display restrained hysteresis and great stability under ambient conditions.