Enabling Highly Efficient and Stable Perovskite Photovoltaics via A Multidentate Molecular Anchor Additive

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face challenges with formamidinium (FA) loss and phase degradation, limiting their efficiency and stability.
• Stabilizing the perovskite structure is crucial for developing high-performance and durable PSCs.

Purpose of the Study:

• To design and synthesize a novel multifunctional additive (ZL1) for stabilizing the α-FAPbI3 perovskite phase.
• To investigate the synergistic multisite interactions of ZL1 with the perovskite structure.
• To evaluate the impact of ZL1 on perovskite film quality, device performance, and operational stability.

Main Methods:

• Synthesis of a novel multifunctional additive (ZL1).
• Characterization of ZL1's interactions with the perovskite lattice through hydrogen bonding, cation-π, Lewis acid-base, and N-H···I interactions.
• Fabrication and testing of ZL1-modified PSC devices and wide-bandgap PSCs.
• Assessment of device performance (power conversion efficiency) and operational stability under illumination and thermal stress.

Main Results:

• ZL1 effectively suppresses FA loss and perovskite phase degradation by forming synergistic multisite interactions.
• ZL1 treatment optimizes perovskite crystallization, leading to enlarged grain sizes and reduced defect density.
• ZL1-modified PSCs achieved a power conversion efficiency of 26.13% (vs. 24.20% for control).
• Wide-bandgap PSCs showed improved efficiency from 18.44% to 20.53% with ZL1.
• Unencapsulated ZL1-based devices demonstrated exceptional operational stability.

Conclusions:

• ZL1 is a highly effective additive for stabilizing α-FAPbI3 perovskite films and enhancing PSC performance.
• The multifunctional nature of ZL1 contributes to improved device efficiency and long-term operational stability.
• ZL1 represents a promising strategy for advancing the commercial viability of perovskite solar cells.