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

Abstract

Perovskite solar cells (PSCs) have achieved unprecedented power conversion efficiency improvements, and further development is stepping to industrialization. In terms of industrial manufacturing, simplifying the solar cell structure is critical in both fabrication process design and cost control. Due to the bipolar charge transport nature of perovskites, the elimination of the charge carrier transport layer is possible. Herein, EMIMPF6 ionic liquid is incorporated into the perovskite film to modulate the energy‐level alignment and the charge transfer kinetics, demonstrating a high‐performance electron transport layer‐free (ETL‐free) PSC. The integrated EMIMPF6 assisted the internal charge collection and favored the interfacial charge transfer from perovskite to FTO substrate, contributing to the high performance of ETL‐free PSCs. The ETL‐free PSCs showed a conversion efficiency of 16.2%, which is comparable with its conventional counterpart. This work provides a solution to simplify the PSC structure and would have an impact on designing a scalable manufacturing process for PSCs.

Balancing Lattice Strain by Embedded Ionic Liquid for the Stabilization of Formamidinium-Based Perovskite Solar Cells

“…The FTO glasses were washed consecutively in deionized water, acetone, isopropanol, and anhydrous ethanol by sequential sonication, dried, and treated with oxygen plasma for 15 min. The compact TiO 2 solution, the mesoporous TiO 2 paste, and the Spiro-OMeTAD solution were prepared according to our previous work . Specifically, the compact TiO 2 solution was spin-coated on precleaned FTO glass substrate at 3500 rpm for 35 s, and then dried at 80 °C for 10 min.…”

“…The J–V curves of the devices were measured using a Keithley 2400 source meter under simulated AM 1.5 G (100 mW/cm 2 irradiance) from a solar simulator (Oriel, model 91192-1000). The complete PSC device was composed of FTO glass/ETL/perovskite/HTL/Au, and the active area was 0.096 cm 2 …”

“…The compact TiO 2 solution, the mesoporous TiO 2 paste, and the Spiro-OMeTAD solution were prepared according to our previous work. 34 Specifically, the compact TiO 2 solution was spin-coated on precleaned FTO glass substrate at 3500 rpm for 35 s, and then dried at 80 °C for 10 min. The mesoporous TiO 2 layer was fabricated by spin coating the mesoporous TiO 2 paste on top of the compact layer at the speed of 6000 rpm for 55 s and annealed at 500 °C for 30 min.…”

“…The complete PSC device was composed of FTO glass/ETL/perovskite/HTL/Au, and the active area was 0.096 cm 2 . 34 ■ ASSOCIATED CONTENT * sı Supporting Information…”

Configuration of Methylammonium Lead Iodide Perovskite Solar Cell and its Effect on the Device's Performance: A Review

“…[361] Similarly, Duan incorporated 1-ethyl-3-methylimidazolium hexafluorophosphate (EMIMPF 6 ) ionic liquid into the perovskite film and demonstrated a high-performance electron transport layer-free (ETL-free) PSC. [362] Subsequently, Jang et al employed a bathocuproine (BCP) interlayer between the graphene (GR) transparent conductive electrode and the GQDs-added MAPbI 3 perovskite layer. The BCP interlayer effectively enhances the electron carrier injection by reducing the recombination centers at the interface.…”