In Situ Hole-Transport Layer Formation and Concurrent Passivation for FA_0.9Cs_0.1PbI₃ Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• The interface between the hole transport layer (HTL) and perovskite layer is crucial for inverted perovskite solar cells (PSCs) efficiency and stability.
• Conventional methods for HTL fabrication face challenges like poor wetting, high defect densities, and scalability issues.

Purpose of the Study:

• To introduce a dynamic self-assembly (DSA) approach for simultaneous HTL fabrication and perovskite passivation in a single step.
• To overcome the limitations of sequential deposition methods in PSCs.

Main Methods:

• Integrating a binary mixture of self-assembled monolayers (SAMs) and a monomer (DMAEMA) into the perovskite precursor.
• Utilizing in situ formation of a uniform HTL during perovskite crystallization via DSA.
• Employing SAMs for energy alignment and interfacial contact, and polymerized DMAEMA for defect passivation at grain boundaries.

Main Results:

• Achieved a champion power conversion efficiency (PCE) of 22.03% with a high open-circuit voltage (Voc) of 1.11 V.
• Demonstrated improved film crystallinity, interfacial homogeneity, and reduced non-radiative recombination.
• Showcased operational stability under prolonged maximum power point tracking under continuous illumination and elevated temperature.

Conclusions:

• Dynamic self-assembly (DSA) is an effective strategy for simultaneous buried interface engineering and defect passivation in inverted PSCs.
• The DSA approach significantly enhances both the efficiency and stability of perovskite solar cells.
• This method offers a scalable and efficient route for fabricating high-performance PSCs.