Efficient Air-Processed Green-Solvent Based Organic Solar Cells Fabricated via Facile Extremely Low-Temperature...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Air-processed organic solar cells (OSCs) show lower power conversion efficiencies (PCEs) than glove-box processed ones.
• Challenges include controlling nanomorphology and charge-carrier transport in air-processed OSCs.

Purpose of the Study:

• To develop a strategy for efficient air-processed OSCs using halogen-free solvents.
• To precisely control material crystallinity and packing in the film state.

Main Methods:

• An extremely low-temperature induced crystallization (ELTC) strategy was employed.
• Modulated crystallinity and packing motifs of photoactive materials from solution to film state.
• Utilized a halogen-free solvent system.

Main Results:

• Achieved densely packed molecular ordering of polymers and nonfullerene acceptors.
• Tuned nanomorphology, accelerated interfacial hole-transport, and heightened charge-carrier transport.
• Obtained PCEs over 18% for binary and ~19% for ternary air-processed OSCs.

Conclusions:

• The ELTC strategy is crucial for fabricating efficient air-processed OSCs.
• Manipulating molecular packing motifs and reducing stacking distances enhances device performance.
• This approach advances the development of high-efficiency OSCs processed without hazardous solvents.