Self-Polymerized Spiro-Type Interfacial Molecule toward Efficient and Stable Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Spiro-OMeTAD is a key material for high-efficiency perovskite solar cells (PSCs).
• However, spiro-OMeTAD's stability issues hinder the commercialization of PSCs.
• Improving device longevity is crucial for widespread adoption of PSC technology.

Purpose of the Study:

• To synthesize and characterize a novel self-polymerized spiro-type interfacial molecule, v-spiro.
• To investigate the potential of v-spiro to enhance both efficiency and stability in PSCs.
• To address the critical stability bottleneck in perovskite solar cell development.

Main Methods:

• Synthesis of a novel spiro-type molecule, v-spiro, with vinyl groups for in situ polymerization.
• Fabrication of perovskite solar cells utilizing the poly-v-spiro interfacial layer.
• Performance and stability testing of the fabricated devices under various stress conditions (humidity, light exposure).

Main Results:

• The synthesized v-spiro molecule exhibits enhanced intermolecular interactions and hole mobility compared to spiro-OMeTAD.
• In situ polymerization of v-spiro forms a protective layer, effectively suppressing moisture degradation and ion migration.
• Poly-v-spiro based PSCs achieved a power conversion efficiency of 24.54%, with improved open-circuit voltage and fill factor.
• Devices demonstrated remarkable operational stability, retaining over 90% of initial efficiency after 2000 hours under 60% humidity and 1250 hours under continuous sunlight.

Conclusions:

• The novel poly-v-spiro interfacial layer significantly enhances both the power conversion efficiency and operational stability of perovskite solar cells.
• This innovative interfacial design offers a promising strategy to overcome the stability limitations of PSCs.
• The developed material and approach pave the way for commercially viable, high-performance perovskite solar cells.