Improved Short-Circuit Current and Fill Factor in PM6:Y6 Organic Solar Cells through D18-Cl Doping

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic solar cells (OSCs) offer a promising alternative to silicon-based photovoltaics due to their flexibility and low-cost fabrication.
• Ternary blends, incorporating a third component into binary systems, are increasingly explored to optimize OSC performance.
• The PM6:Y6 system is a well-established benchmark for high-performance binary organic solar cells.

Purpose of the Study:

• To investigate the impact of doping a novel non-fullerene acceptor, D18-Cl, into the PM6:Y6 binary system on organic solar cell performance.
• To determine the optimal doping ratio of D18-Cl for maximizing the power conversion efficiency (PCE) of ternary organic solar cells.
• To elucidate the underlying mechanisms responsible for performance enhancement.

Main Methods:

• Fabrication of ternary organic solar cells using PM6:Y6 blended with varying weight percentages of D18-Cl.
• Performance characterization including measurements of short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE).
• Analysis of optical absorption spectra and active layer morphology to understand performance improvements.

Main Results:

• The optimal doping ratio of D18-Cl was found to be 20 wt%, yielding a PCE of 16.08%.
• This ternary blend exhibited a Jsc of 28.13 mA/cm², FF of 70.25%, and Voc of 0.81 V.
• Doping with D18-Cl led to an expanded absorption spectrum, improved active layer morphology, reduced aggregation and defects, minimized recombination, and enhanced charge carrier collection.

Conclusions:

• The strategic incorporation of a third component, D18-Cl, significantly enhances the performance of PM6:Y6 based organic solar cells.
• Optimizing the doping ratio is crucial for achieving superior device performance in ternary organic solar cells.
• This study highlights the potential of ternary systems for advancing organic photovoltaic technology.