Molecular Polarization-Driven Synergistic Interface Engineering for High-Performance Perovskite Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face performance limitations due to interfacial issues like non-radiative recombination and poor carrier transport.
• Inhomogeneous distribution and weak bonding of self-assembled monolayers (SAMs) at the SAM/perovskite interface exacerbate these problems.

Purpose of the Study:

• To develop a universal interface engineering strategy for enhancing PSC performance.
• To address challenges of non-radiative recombination and carrier transport losses at the SAM/perovskite interface.

Main Methods:

• Employed 2-aminopyrimidine-4-carboxylic acid (m-APCA) for synergistic interface engineering.
• m-APCA features asymmetric bifunctional groups, inducing molecular polarization and reinforcing π-π interactions with SAMs.
• Utilized m-APCA's dipole field and chemistry for robust bonding with the perovskite layer, regulating grain growth and passivating defects.

Main Results:

• Achieved high power conversion efficiencies (PCEs) of 26.77% (small-area), 26.08% (centimeter-scale), and 24.17% (wide-bandgap) PSCs.
• Demonstrated enhanced hole transport efficiency and reduced interfacial energy barriers.
• Optimized PSCs retained 96% of initial efficiency after 1200 hours of continuous operation, indicating exceptional stability.

Conclusions:

• The m-APCA strategy effectively mitigates SAM aggregation and ensures uniform coverage.
• m-APCA acts as nucleation sites, improving perovskite film quality and passivating interfacial defects.
• This approach offers a universal solution for high-performance and stable perovskite solar cells.