A medium bandgap dimeric acceptor with a high open-circuit voltage for efficient organic solar cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Dimeric acceptors (DMAs) are crucial for enhancing organic solar cell (OSC) efficiency and stability.
• Medium band-gap DMAs with high open-circuit voltage (Voc) are underexplored but vital for high-performance OSCs.

Purpose of the Study:

• To design and synthesize a novel medium band-gap dimeric acceptor (DYO-1) for OSC applications.
• To investigate the impact of alkoxy side-chain substitutions on DMA properties and OSC performance.
• To achieve high power conversion efficiency (PCE) and open-circuit voltage (Voc) in OSCs using DYO-1.

Main Methods:

• Synthesis of DYO-1 via alkoxy side-chain substitutions.
• Fabrication of OSC devices using PM6:DYO-1 binary and PM6:L8-BO-X:DYO-1 ternary blends.
• Characterization of material properties, including LUMO levels and absorption spectra.
• Performance evaluation of OSC devices, including Voc, fill factor (FF), short-circuit current (Jsc), and PCE.
• Fabrication and testing of a large-area module device.

Main Results:

• DYO-1 exhibits an upshifted LUMO level and blue-shifted absorption.
• A PM6:DYO-1 binary OSC achieved a record Voc of 1.022 V and PCE of 15.1%.
• A PM6:L8-BO-X:DYO-1 ternary OSC reached a prominent PCE of 19.6% with improved carrier transport.
• A 13.5 cm² module device demonstrated a PCE of 15.8%, indicating large-area fabrication potential.

Conclusions:

• Medium band-gap dimeric acceptors are critical for developing efficient and stable OSCs.
• DYO-1 represents a significant advancement in electron acceptor design for high-performance OSCs.
• The study provides valuable insights for designing next-generation high-performance electron acceptors for organic photovoltaics.