Efficient Inorganic Vapor-Assisted Defects Passivation for Perovskite Solar Module

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Surface traps from intrinsic defects cause non-radiative recombination, hindering high-efficiency perovskite solar cell fabrication.
• Ion migration in perovskite materials leads to iodine vacancies and uncoordinated Pb2+ defects.

Purpose of the Study:

• To develop a CS2 vapor-assisted passivation method for perovskite solar modules.
• To address defects like iodine vacancies and uncoordinated Pb2+ caused by ion migration.
• To improve perovskite device efficiency and operational stability.

Main Methods:

• A carbon disulfide (CS2) vapor-assisted passivation technique was employed.
• The strategy aimed to passivate iodine vacancies and uncoordinated Pb2+ defects.
• Characterization of defect formation energy and device performance was conducted.

Main Results:

• CS2 vapor passivation increased the defect formation energy of iodine vacancies from 0.37 eV to 0.54 eV.
• Uncoordinated Pb2+ defects were effectively bonded with CS2.
• Enhanced device efficiencies of 25.20% (0.08 cm2) and 20.66% (40.6 cm2) were achieved.
• Improved stability was demonstrated with an average T80 lifetime of 1040 hours and >90% efficiency retention after 2000 hours under specific conditions.

Conclusions:

• CS2 vapor passivation is a viable strategy to mitigate defects in perovskite solar cells.
• This method offers advantages over traditional spin-coating techniques, avoiding film inhomogeneity and solvent-induced surface reconstruction.
• The enhanced efficiency and stability pave the way for reliable, large-area perovskite photovoltaic applications.