Tackling Energy Loss in Organic Solar Cells via Volatile Solid Additive Strategy

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Energy loss, particularly the open-circuit voltage (VOC) deficit, significantly hinders the performance of organic solar cells (OSCs).
• Developing effective strategies to minimize energy loss is crucial for advancing OSC technology.

Purpose of the Study:

• To introduce a novel volatile solid additive, 1,4-bis(iodomethyl)cyclohexane (DIMCH), as a morphology-directing agent.
• To investigate the impact of DIMCH on reducing energy loss in state-of-the-art organic solar cell systems.
• To enhance the efficiency of binary organic solar cells.

Main Methods:

• Utilizing DIMCH as a volatile solid additive during the film formation process in OSCs.
• Analyzing the effect of DIMCH on the crystallinity of donor and acceptor materials.
• Evaluating the impact of DIMCH on the homogeneity of the blend morphology and phase separation.
• Assessing changes in energy disorder and trap density within the OSCs.

Main Results:

• Achieved a high power conversion efficiency of 18.8% in binary OSCs, placing it at the forefront of reported devices.
• DIMCH effectively balanced the crystallinity of donor and acceptor materials, leading to a homogeneous network structure.
• Reduced domain phase separation and weakened energy disorder and trap density in the OSC films.
• Demonstrated a decrease in radiative and non-radiative recombination induced energy loss (ΔE2/ΔE3).

Conclusions:

• The volatile solid additive DIMCH serves as an effective morphology-directing guest to mitigate energy loss in OSCs.
• This approach offers a promising strategy for further reducing energy loss and improving the performance of organic solar cells.
• The study provides valuable insights into the role of volatile solid additives in OSC development.