Tailored Electron-Deficient Macrocycles Guiding the Perovskite Crystallization Process for Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) show high power conversion efficiencies (PCEs).
• PSC commercialization is hindered by poor operational stability due to defects and halide ion migration.
• Existing strategies struggle to effectively address these stability issues.

Purpose of the Study:

• To develop a novel additive for enhancing PSC stability and performance.
• To investigate the role of a new macrocycle molecule in regulating perovskite crystallization and inhibiting ion migration.
• To reduce intrinsic defects in perovskite films through targeted molecular interactions.

Main Methods:

• Synthesis of an electron-deficient biphen[n]arene macrocycle molecule (NBP[2]) via condensation reaction.
• Incorporation of NBP[2] into perovskite films using the antisolvent injection method.
• Characterization of NBP[2]-modified PSCs under prolonged operational stress (1000 h maximum power point tracking).

Main Results:

• NBP[2] acted as a crystallization regulator and halide anion migration inhibitor in perovskite films.
• The molecule reduced intrinsic defects by interacting with uncoordinated ions and Pb2+ via Lewis acid-base and cation-π mechanisms.
• NBP[2]-modified PSCs achieved a peak PCE of 25.38% (vs. 23.89% for control).
• Modified PSCs retained 95.8% of initial efficiency after 1000 hours of operation.

Conclusions:

• The novel NBP[2] molecule effectively enhances both the efficiency and long-term stability of perovskite solar cells.
• NBP[2] offers a promising strategy for overcoming key limitations in perovskite photovoltaic technology.
• This approach demonstrates the potential of tailored molecular design for advanced energy materials.