Dipole-Moment-Tuned Self-Assembled Monolayers for Efficient Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Self-assembled monolayers (SAMs) are crucial as hole transport layers (HTLs) in perovskite solar cells (PSCs).
• Limitations in SAMs include poor wettability, nonuniform coverage, and defects, hindering device performance.
• Interfacial engineering is key to overcoming these challenges in PSCs.

Purpose of the Study:

• To develop an interfacial engineering strategy for enhancing perovskite solar cell performance.
• To investigate the effect of incorporating 2-fluorobenzene-1,3-dicarboxylic acid (m-FBC) into SAMs.
• To improve energy level alignment, wettability, and reduce electronic inhomogeneity at the substrate-perovskite interface.

Main Methods:

• Fabrication of perovskite solar cells using SAMs modified with 2-fluorobenzene-1,3-dicarboxylic acid (m-FBC).
• Characterization of interfacial properties, including energy level alignment, wettability, and electronic homogeneity.
• Performance testing of the modified PSCs, including power conversion efficiency (PCE) and long-term stability.

Main Results:

• The m-FBC modified SAMs effectively aligned energy levels, reducing the charge-transport energy barrier.
• Enhanced surface wettability and mitigated electronic inhomogeneity were observed at the buried interface.
• The modified PSCs achieved a peak power conversion efficiency (PCE) of 25.03%, a significant improvement over the control device's 23.05%.
• Optimized devices retained 94% of their initial efficiency after 500 hours of storage, demonstrating improved stability.

Conclusions:

• The incorporation of m-FBC into SAMs is a promising strategy for multifunctional hole transport layers in PSCs.
• This interfacial engineering approach effectively enhances device performance and stability.
• The study provides valuable insights into structure-property relationships of SAMs in inverted PSCs.