Coordination Cathode Interlayer Enhancing the Stability of Air-Processed Organic Photovoltaics

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic photovoltaic (OPV) devices suffer performance degradation due to moisture-induced charge recombination.
• The interface between the electron transport layer (ETL) and the top electrode is particularly vulnerable to moisture ingress.

Purpose of the Study:

• To enhance the moisture resistance and air stability of OPV devices.
• To improve the power conversion efficiency (PCE) of unencapsulated OPV devices.

Main Methods:

• Modification of the interface between ZnO nanoparticles (ZnO NPs) ETL and the Ag electrode using a coordination interlayer.
• Strengthening adhesion between the ZnO NPs layer and the Ag electrode to prevent moisture invasion.

Main Results:

• A substantial increase in PCE from 0.1% to 16.3% for unencapsulated devices under open-air conditions.
• Significant retention of initial PCE: 85% after 14 days and 56% after 1 year of air storage.
• Dramatically improved moisture resistance at the ETL-electrode interface.

Conclusions:

• The coordination interlayer is an effective strategy for enhancing the moisture resistance and stability of OPV devices.
• This modification leads to remarkable improvements in device performance and longevity.
• The developed method offers a promising pathway for developing durable and efficient unencapsulated OPV devices.