A Versatile Ionic Liquid Additive for Perovskite Solar Cells: Surface Modification, Hole Transport Layer Doping, and...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Hole-transport layers (HTLs) in perovskite solar cells (PSCs) are crucial for efficient charge extraction.
• Traditional dopants like LiTFSI face limitations including environmental concerns and stability issues.
• Developing stable and efficient HTLs is key to advancing PSC technology.

Purpose of the Study:

• To explore a novel ionic liquid, MMPyTFSI, as an alternative dopant for spiro-OMeTAD in PSCs.
• To evaluate the performance and stability of PSCs using MMPyTFSI as a dopant.
• To assess the environmental benefits of using MMPyTFSI compared to conventional dopants.

Main Methods:

• Synthesis and characterization of the ionic liquid 1-(2-methoxyethyl)-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (MMPyTFSI).
• Fabrication of PSCs using spiro-OMeTAD doped with MMPyTFSI, with THF as a solvent.
• Performance testing including power conversion efficiency (PCE) measurements.
• Long-term stability assessments under various stress conditions (humidity, temperature, light).

Main Results:

• PSCs with MMPyTFSI dopant achieved a power conversion efficiency (PCE) of 23.10%.
• MMPyTFSI demonstrated effective p-type doping and surface passivation, reducing perovskite defects.
• The optimized PSCs exhibited enhanced long-term stability, exceeding 1000 hours under accelerated aging conditions.
• Utilizing THF as a solvent with MMPyTFSI maintained high performance and reduced environmental impact.

Conclusions:

• MMPyTFSI is a highly effective and environmentally friendly dopant for PSCs.
• This ionic liquid dopant significantly improves both the efficiency and long-term stability of perovskite solar cells.
• MMPyTFSI offers a promising alternative to conventional dopants, paving the way for more sustainable and robust PSCs.