A Strategy to Produce High Efficiency, High Stability Perovskite Solar Cells Using Functionalized Ionic Liquid‐Dopants

Abstract

Functionalized imidazolium iodide salts (ionic liquids) modified with CH CHCH , CH CCH, or CH CN groups are applied as dopants in the synthesis of CH NH PbI -type perovskites together with a fumigation step. Notably, a solar cell device prepared from the perovskite film doped with the salt containing the CH CHCH side-chain has a power conversion efficiency of 19.21%, which is the highest efficiency reported for perovskite solar cells involving a fumigation step. However, doping with the imidazolium salts with the CH CCH and CH CN groups result in perovskite layers that lead to solar cell devices with similar or lower power conversion efficiencies than the dopant-free cell.

Causes and Solutions of Recombination in Perovskite Solar Cells

“…Seo et al incorporated an ionic liquid methylammonium formate (MAF) into perovskite precursor solution to prepare high‐quality perovskite film. Additionally, Zhang et al used functionalized imidazolium iodide modified with CH 2 CHCH 2 (CC2), CH 2 CCH (CC3), or CH 2 CN (CN) groups and found that the tested ionic liquids increases MAPbI 3 grain size but only CC2‐functionalized ionic liquid improved PL decay lifetime and PCE. They also studied physical properties of (CC2)PbI 3 , (CC3)PbI 3 and (CN)PbI 3 .…”

Self‐Assembled Ionic Liquid for Highly Efficient Electron Transport Layer‐Free Perovskite Solar Cells

“…Ionic liquids have been widely applied in lithium‐ion batteries, dye‐sensitized solar cells, and organic solar cells because of their unique merits. Although there have been several reports on ionic liquids used as interfacial layers to modify ETLs such as SnO 2 and TiO 2 for ETL‐containing PSCs, to our knowledge, the self‐assembly of ionic liquids on the conductive substrate has not been reported to date for the ETL‐free PSCs.…”

Superfast Room‐Temperature Activation of SnO2 Thin Films via Atmospheric Plasma Oxidation and their Application in Planar Perovskite Photovoltaics

“…With the mixed form of perovskites, a power conversion efficiency (PCE) of over 20% have been frequently achieved with “n–i–p”‐type PSC, and the PCE approaches the theoretical limit. Now academic interests are focused on resolving the practical issues necessary for PSC commodification, i.e., large‐scale operation, working stability, low‐temperature (LT) fabrication, and process simplicity …”