Pow(d)ering up: FAPI perovskite nanopowders for air-processed blade coated perovskite solar modules

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Formamidinium lead iodide (FAPI) is key for perovskite solar cells.
• Thermodynamic instability of cubic α-phase FAPI in solution leads to inefficient δ-phase formation.
• Developing stable FAPI precursor solutions is crucial for efficient perovskite solar cell fabrication.

Purpose of the Study:

• To demonstrate the fabrication of stable perovskite solar cells and modules from pre-synthesized FAPI powders.
• To investigate a scalable, cost-effective, and environmentally friendly synthesis method for FAPI.
• To enhance the stability and reproducibility of perovskite solar devices.

Main Methods:

• Single-step synthesis of FAPI powders using a non-hazardous solvent and routine purity lead iodide.
• Fabrication of small-area cells and mini-modules using blade coating in an open environment.
• Analysis of solution rheology, stoichiometry control, and crystal lattice properties.

Main Results:

• Pre-synthesized α-FAPI and CsFAPI powders show scalability and reproducibility.
• Similar efficiencies achieved in cells and mini-modules fabricated via blade coating.
• Enhanced solution rheology and stoichiometry control led to oriented, less strained crystal lattices.
• Perovskite from pre-synthesized powder exhibited superior reproducibility and stability over high-purity precursor methods.
• Module efficiencies reached 18.5% (12.15 cm²), with T95 stability exceeding 1200 hours (30% RH, UV-filtered).

Conclusions:

• The developed methodology offers a scalable and cost-effective approach for producing high-performance, stable perovskite solar modules.
• Pre-synthesized FAPI powders significantly improve the stability and reproducibility of perovskite solar cells.
• This approach addresses the challenge of α-phase instability in FAPI precursor solutions, paving the way for industrial application.