Amine-based polar solvent treatment for highly efficient inverted polymer solar cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Polymer solar cells (PSCs) are a promising renewable energy technology.
• Efficient charge extraction is crucial for high-performance PSCs.
• Interfacial engineering plays a key role in optimizing PSC performance.

Purpose of the Study:

• To investigate the effect of interfacial dipolar polarization on inverted structure PSCs.
• To understand the role of ethanolamine end groups on zinc oxide (ZnO-R) interfaces.
• To correlate interfacial properties with device performance metrics.

Main Methods:

• Fabrication of inverted structure polymer solar cells with ripple-structure zinc oxide (ZnO-R) layers.
• Characterization of interfacial properties using techniques sensitive to polarization effects.
• Analysis of electron transport, recombination dynamics, and electrical resistance.

Main Results:

• Spontaneous interfacial dipolar polarization observed due to ethanolamine end groups (amine, hydroxyl) on ZnO-R.
• Lowered contact barrier for electron transport and extraction.
• Enhanced electron mobility and suppressed bimolecular recombination.
• Reduced contact and series resistance.
• Remarkable enhancement in power conversion efficiency.

Conclusions:

• Interfacial dipolar polarization is a key mechanism for improving electron transport in PSCs.
• Surface functionalization of ZnO-R with ethanolamine groups effectively enhances device performance.
• This study provides insights for designing advanced interfaces in organic solar cells.