Single-Junction Organic Photovoltaic Cell with 19% Efficiency

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Improving power conversion efficiency (PCE) is crucial for the commercial viability of organic photovoltaic (OPV) cells.
• Novel material design and ternary blending strategies are key to advancing OPV performance.

Purpose of the Study:

• To achieve high PCE in single-junction OPV cells.
• To explore the synergistic effects of ternary blending with new donor and acceptor materials.

Main Methods:

• Rational design of a wide-bandgap polymer donor (PBQx-TF) and a low-bandgap non-fullerene acceptor (NFA, eC9-2Cl).
• Incorporation of a third NFA (F-BTA3) into the active layer to form a ternary blend.
• Optimization of light utilization, energy level alignment, and intermolecular packing.

Main Results:

• A maximum PCE of 19.0% (certified 18.7%) was achieved in single-junction OPV cells.
• The binary blend of PBQx-TF:eC9-2Cl reached a PCE of 17.7%.
• The ternary blend demonstrated improved open-circuit voltage (0.879 V), short-circuit current density (26.7 mA cm⁻²), and fill factor (0.809).

Conclusions:

• Ternary blending is an effective strategy for enhancing OPV performance.
• Fine-tuning electronic structures and morphologies of active layers is essential for further PCE improvements in high-performance OPV cells.