Fluorene- and fluorenone-based molecules as electron-transporting SAMs for photovoltaic devices

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Electron transporting materials (ETMs) are crucial for efficient charge extraction in photovoltaic devices.
• Developing stable and effective ETMs is key to advancing solar cell technology.
• Perovskite, Sb2S3, and Sb2Se3 absorbers require compatible ETMs for optimal performance.

Purpose of the Study:

• To synthesize and investigate novel fluorene/fluorenone-based semiconductors as electron transporting materials.
• To evaluate their thermal stability, electrochemical properties, and interfacial behavior.
• To assess their potential for application in perovskite solar cells.

Main Methods:

• Synthesis of fluorene/fluorenone derivatives with phosphonic acid anchoring groups.
• Characterization of thermal stability and electrochemical properties.
• Investigation of self-assembled monolayers and surface interactions with ITO, TiO2, Sb2S3, and Sb2Se3.

Main Results:

• Synthesized semiconductors exhibit good thermal stability and suitable electrochemical properties for electron transport.
• Self-assembled monolayers show improved substrate wettability, indicating surface bonding.
• Materials possess compatible energetic band alignment and passivate perovskite interface defects.

Conclusions:

• Fluorene and fluorenone derivatives are promising electron transporting materials for photovoltaic applications.
• Their interfacial properties and defect passivation capabilities enhance performance in n-i-p perovskite solar cells.
• These materials offer a viable alternative for improving solar energy conversion efficiency.