Interfacial Molecular Lock Enables Highly Efficient Tin Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Tin perovskite solar cells (TPSCs) suffer from low power conversion efficiency (PCE) and poor stability.
• Key issues include Sn2+ oxidation and iodine ion migration, leading to trap states and carrier recombination.

Purpose of the Study:

• To develop a novel

Main Methods:

• Incorporation of tetrafluoroborate (BF4-) to release lattice strain and enhance structural stability.
• Introduction of myricetin as a natural antioxidant to anchor on perovskite surfaces and grain boundaries via hydrogen bonding.
• Utilizing myricetin to reduce Sn4+ to Sn2+ and stabilize iodine within perovskite octahedrons.

Main Results:

• The developed tin perovskite solar cell achieved a high PCE of 14.08%.
• The device demonstrated excellent stability, with negligible PCE change after 1000 hours of dark storage.
• The solar cell retained 89.9% of its initial PCE after 200 hours of continuous irradiation.

Conclusions:

• The "molecular lock" strategy effectively suppresses tin perovskite oxidation and iodine migration.
• The combination of BF4- and myricetin significantly improves both the efficiency and long-term stability of TPSCs.
• This approach offers a promising pathway for advancing tin perovskite solar cell technology.