Ionic Liquid Additive-Assisted Highly Efficient Electron Transport Layer-Free Perovskite Solar Cells

摘要

Perovskite solar cells (PSCs) have achieved unprecedented power conversionefficiency improvements, and further development is stepping to industrialization.In terms of industrial manufacturing, simplifying the solar cell structure iscritical in both fabrication process design and cost control. Due to the bipolarcharge transport nature of perovskites, the elimination of the charge carriertransport layer is possible. Herein, EMIMPF_6 ionic liquid is incorporated into theperovskite film to modulate the energy-level alignment and the charge transferkinetics, demonstrating a high-performance electron transport layer-free (ETLfree)PSC. The integrated EMIMPF_6 assisted the internal charge collection andfavored the interfacial charge transfer from perovskite to FTO substrate, contributingto the high performance of ETL-free PSCs. The ETL-free PSCs showed aconversion efficiency of 16.2%, which is comparable with its conventionalcounterpart. This work provides a solution to simplify the PSC structure andwould have an impact on designing a scalable manufacturing process for PSCs.