Efficient Functional Compensation Layer Integrated with HTL for Improved Stability and Performance in Perovskite...

Area of Science:

• Materials Science
• Photovoltaics
• Organic Electronics

Background:

• Interface engineering is critical for high-efficiency inverted perovskite solar cells (PSCs).
• Existing hole-transport layers (HTLs) often present challenges in optimizing interfacial contact with perovskite absorbers.

Purpose of the Study:

• To introduce an effective functional compensation layer (FCL) to enhance interfacial properties in PSCs.
• To investigate the impact of a benzothiophene derivative, TFMBTA, as an FCL on PSC performance and stability.

Main Methods:

• Fabrication of inverted PSCs with a MeO-2PACz HTL and introduction of a TFMBTA-based FCL.
• Characterization of interfacial properties, including surface morphology, energy level alignment, and defect passivation.
• Performance evaluation through power conversion efficiency (PCE), open-circuit voltage (Voc), and fill factor (FF) measurements.
• Assessment of long-term operational stability.

Main Results:

• The TFMBTA FCL improved HTL surface morphology and optimized energy level alignment.
• Effective passivation of perovskite defects by TFMBTA functional groups, reducing non-radiative recombination.
• MeO-2PACz-based PSCs with FCL achieved a peak PCE of 23.85%, with enhanced Voc, FF, and stability.
• Demonstrated universality of TFMBTA FCL for enhancing PSCs with different HTLs, including PEDOT:PSS.

Conclusions:

• The TFMBTA-based FCL is a highly effective strategy for improving interfacial characteristics in inverted PSCs.
• This approach leads to significant enhancements in device efficiency, operational stability, and defect mitigation.
• The FCL technology shows broad applicability across various HTL materials in PSCs.