Highly efficient all-inorganic perovskite solar cells with suppressed non-radiative recombination by a Lewis base

Abstract

All-inorganic perovskite solar cells (PVSCs) have drawn increasing attention because of their outstanding thermal stability. However, their performance is still inferior than the typical organic-inorganic counterparts, especially for the devices with p-in configuration. Herein, we successfully employ a Lewis base small molecule to passivate the inorganic perovskite film, and its derived PVSCs achieved a champion efficiency of 16.1% and a certificated efficiency of 15.6% with improved photostability, representing the most efficient inverted all-inorganic PVSCs to date. Our studies reveal that the nitrile (C-N) groups on the small molecule effectively reduce the trap density of the perovskite film and thus significantly suppresses the non-radiative recombination in the derived PVSC by passivating the Pb-exposed surface, resulting in an improved open-circuit voltage from 1.10 V to 1.16 V after passivation. This work provides an insight in the design of functional interlayers for improving efficiencies and stability of all-inorganic PVSCs.

Suppressing Defects‐Induced Nonradiative Recombination for Efficient Perovskite Solar Cells through Green Antisolvent Engineering

“…In addition, the MABrEthPerovskite exhibits an obvious increased PL inten sity compared with EthPerovskite, implying a significant sup pressed nonradiative recombination due to MABr passivates the defects. [27] TRPL results of samples were fitted by biexpo nential decay function with PL lifetime (τ i ) and amplitudes (A 1 ), followed by the equation of in Figure S2 and corresponding parameters are summarized in Table S1 of the Supporting Information. τ 1 is closely related to nonradiative recombination by defects and τ 2 as a component of radiative recombination from perovskite.…”

Chemically Stable Black Phase CsPbI3 Inorganic Perovskites for High‐Efficiency Photovoltaics

“…Besides, some other small molecules, such as a π‐conjugated Lewis base 6TIC‐4F, which contains a strong electron‐donating core and two electron‐withdrawing units, were dissolved in the anti‐solvent to passivate the surface defects on the perovskite thin films, therefore improving the CsPbI 3 perovskite quality. [ 68 ]…”

High‐Efficiency Perovskite Quantum Dot Hybrid Nonfullerene Organic Solar Cells with Near‐Zero Driving Force

“…[ 41–43 ] Recently, it was reported that a nonfullerene Lewis base could passivate inorganic perovskite (CsPbI x Br 3− x ) through interaction between Pb and CN groups/S atoms. [ 44 ] PbI 2 is rich on the surface of PQDs (positively charged), and capping reagents such as oleylamine and oleic acid can passivate the surface. [ 39,45 ] However, the capping reagents are easily removed, resulting in surface defects and degradation of PQDs.…”