Interfacial Modification and Defect Passivation by the Cross-Linking Interlayer for Efficient and Stable CuSCN-Based...

Area of Science:

• Materials Science
• Photovoltaics
• Chemical Engineering

Background:

• Organic hole-transport layers (HTLs) in perovskite solar cells (PSCs) contribute to device degradation.
• Inorganic HTLs offer better stability but present deposition and interfacial control challenges.
• Developing stable and efficient PSCs requires addressing HTL limitations.

Purpose of the Study:

• To introduce polydimethylsiloxane (PDMS) as a stable, cross-linking interlayer for PSCs.
• To investigate PDMS's effect on interfacial properties, photovoltaic performance, and device stability.
• To overcome the limitations of conventional HTLs in PSCs.

Main Methods:

• Demonstration of PDMS as a polymeric interlayer in copper thiocyanate (CuSCN)-based PSCs.
• Utilizing Raman spectroscopy to confirm chemical bonding between PDMS, perovskite, and CuSCN.
• Evaluating photovoltaic performance and long-term stability under various environmental conditions.

Main Results:

• PDMS forms chemical bonds with perovskite and CuSCN, acting as a cross-linking agent.
• The PDMS interlayer enhances hole transport and passivates interfacial defects.
• Achieved a high power conversion efficiency exceeding 19% in PSCs.
• Demonstrated significantly improved stability against humidity and heat, retaining over 90% efficiency after 1000 hours ambient and 500 hours 85°C/85% RH exposure.

Conclusions:

• PDMS is an effective interlayer for enhancing PSC performance and stability.
• The cross-linking behavior of PDMS mitigates interfacial degradation and improves charge transport.
• PDMS-interlayered PSCs show remarkable long-term operational stability, crucial for commercial viability.