Solvent-Free Method for Defect Reduction and Improved Performance of p-i-n Vapor-Deposited Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells are nearing commercialization, necessitating scalable defect passivation methods.
• Vapor deposition is an industrially relevant, solvent-free technique for fabricating perovskite thin films.

Purpose of the Study:

• To enhance the optoelectronic properties and performance of vapor-deposited perovskite solar cells.
• To investigate the impact of substituting lead iodide (PbI2) for lead chloride (PbCl2) in the inorganic precursor.

Main Methods:

• Fabrication of [CH(NH2)2]0.83Cs0.17PbI3 perovskite thin films using vapor deposition.
• Partial substitution of PbI2 for PbCl2 as the inorganic precursor in the deposition process.
• Characterization of film properties, including photoluminescence lifetime, quantum yield, charge-carrier mobility, and solar cell power conversion efficiency.

Main Results:

• Partial substitution of PbI2 for PbCl2 significantly improved photoluminescence lifetimes (5.6 ns to >100 ns) and quantum yields (by over an order of magnitude).
• Charge-carrier mobility increased from 46 cm2/(V s) to 56 cm2/(V s).
• Solar cell power conversion efficiency improved from 16.4% to 19.3% with 20% PbI2 substitution.

Conclusions:

• Partial substitution of PbI2 for PbCl2 is an effective strategy for reducing nonradiative recombination in vapor-deposited perovskite solar cells.
• This scalable, dry, and solvent-free method offers a promising route to high-performance perovskite photovoltaics.