Transition Metal-Oxide Free Perovskite Solar Cells Enabled by a New Organic Charge Transport Layer

TitleTransition Metal-Oxide Free Perovskite Solar Cells Enabled by a New Organic Charge Transport Layer
Publication TypeJournal Article
Year of Publication2016
AuthorsChang, S, Han, GDdeul, Weis, JG, Park, H, Hentz, O, Zhao, Z, Swager, TM, Gradecak, S
JournalAcs Applied Materials & Interfaces
Volume8
Issue13
Pagination8511 - 8519
Date Published2016/04/06/
ISBN Number1944-8244
Keywordsblends, ch3nh3pbi3, cycloaddition, degradation, deposition, electron transfer layer, fullerene derivative, organic charge transport, organic/inorganic hybrid solar cell, perovskite solar cell, polymers, route, temperature
Abstract

Various electron and hole transport layers have been used to develop high-efficiency perovskite solar cells. To achieve low-temperature solution processing of perovskite solar cells, organic n-type materials are employed to replace the metal oxide electron transport layer (ETL). Although PCBM (phenyl C-61 -butyric acid methyl ester) has been widely used for this application, its morphological instability in films (i.e., aggregation) is detrimental. Herein, we demonstrate the synthesis of a new fullerene derivative (isobenzofulvene-C-60 epoxide, IBF-Ep) that serves as an electron transporting material for methylammonium mixed lead halide-based perovskite (CH3NH3PbI3-xClx) solar cells, both in the normal and inverted device configurations. We demonstrate that IBF Ep has superior morphological stability compared to the conventional acceptor, PCBM. IBF Ep provides higher photovoltaic device performance as compared to PCBM (6.9% vs 2.S% in the normal and 9.0% vs S.3% in the inverted device configuration). Moreover, IBF Ep devices show superior tolerance to high humidity (90%) in air. By reaching power conversion efficiencies up to 9.0% for the inverted devices with IBF Ep as the ETL, we demonstrate the potential of this new material as an alternative to metal oxides for perovskite solar cells processed in air.

Short TitleACS Appl. Mater. Interfaces