Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) suffer from surface and grain boundary defects, limiting their performance and stability.
• Molecular modulators are effective for defect passivation in perovskite materials.
• Undercoordinated defects are a key issue affecting charge recombination in PSCs.

Purpose of the Study:

• To investigate the use of crown ethers as molecular modulators for perovskite films.
• To passivate undercoordinated surface defects in perovskite solar cells.
• To elucidate the interaction between crown ethers and perovskite surfaces.

Main Methods:

• Application of crown ethers to perovskite films.
• Solid-state nuclear magnetic resonance (ssNMR) spectroscopy.
• Density functional theory (DFT) calculations.
• Photovoltaic performance characterization.
• Stability testing under ambient and operational conditions.

Main Results:

• Crown ethers form host-guest complexes on perovskite surfaces, passivating defects.
• Nonradiative recombination was suppressed by 40% due to defect passivation.
• Moisture permeation was minimized by the crown ether treatment.
• Power conversion efficiencies exceeded 23% with enhanced device stability.

Conclusions:

• Crown ethers are effective supramolecular modulators for perovskite films.
• This approach significantly improves the photovoltaic performance and stability of PSCs.
• Supramolecular chemistry offers a new strategy for advancing perovskite optoelectronic devices.