Copper Substrate Electrode for Efficient Top-illuminated Organic Photovoltaics

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Large-scale manufacturing of solution-processed organic photovoltaics (OPVs) requires thicker photoactive layers than the current ≤150 nm.
• Silver (Ag) is a common reflective electrode material, but its high cost hinders mass production.

Purpose of the Study:

• To investigate copper (Cu) as a cost-effective alternative to silver for reflective substrate electrodes in high-performance, top-illuminated OPVs.
• To determine if copper electrodes maintain device efficiency with increased photoactive layer thickness.

Main Methods:

• Fabrication of top-illuminated OPVs with varying photoactive layer thicknesses.
• Utilized copper as the reflective substrate electrode, replacing traditional silver.
• Evaluated device power conversion efficiency (PCE) and optical absorption.

Main Results:

• Copper electrodes maintained high device power conversion efficiency in OPVs with sufficiently thick photoactive layers.
• Thicker photoactive layers (optimized for absorption) allowed for the effective use of copper as a reflective electrode.
• Copper is approximately 100 times less expensive than silver, significantly reducing material costs.

Conclusions:

• Copper is a viable and cost-effective alternative to silver for reflective electrodes in large-scale OPV manufacturing.
• Optimizing photoactive layer thickness is crucial for achieving high efficiency with copper electrodes.
• This substitution can substantially lower the bill of materials for OPV production.