Two-in-one additive-engineering strategy for improved air stability of planar perovskite solar cells

Abstract

The stability issue of organic-inorganic halide perovskite solar cells (PSCs) has become obstruction for their practical applications, although they have attained rapid growth in power conversion efficiency (PCE). Here, we demonstrate a two-in-one additive-engineering strategy by doping organic additives benzoquinone (BQ) into MAPbI3 film and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) into hole transport layer (HTL) in a single device, resulting in efficient PSCs with enhanced air stability. The BQ and the F4TCNQ can respectively improve the crystal quality of the MAPbI3 film and increase the moisture tolerance of HTL. The two additives suppress the charge recombination and take a synergistic effect on reduction of traps, contributing to the long-term air stability of unencapsulated planar PSCs. The resulting PSCs with a PCE over 16% can maintain 95% of their initial efficiency after 1400h in ambient air environment. This strategy provides a new way for the air stability enhancement of PSCs by engineering the perovskite layer and HTL with organic additives in a meanwhile.