Stable and Low-Cost Organic Photovoltaics Without Conjugated Donors

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic photovoltaics (OPVs) achieve high power conversion efficiencies (PCEs) but suffer from poor stability due to conventional organic donor and hole transport layers.
• Industrialization of OPVs is hindered by the limited operational lifetime and degradation under thermal stress.

Purpose of the Study:

• To investigate the use of inorganic copper(I) thiocyanate (CuSCN) as a multifunctional material in OPVs.
• To enhance the stability and durability of organic photovoltaic devices using CuSCN.

Main Methods:

• Fabrication of bulk heterojunction organic photovoltaic devices utilizing CuSCN as both donor and hole transport layer.
• Integration of CuSCN with the non-fullerene acceptor L8-BO.
• Performance and stability testing under thermal stress (85°C) and operational conditions (ISOS-L-3 protocol).

Main Results:

• A champion PCE of 7.21% was achieved for the CuSCN/L8-BO based device.
• Exceptional thermal stability was demonstrated, with devices retaining 80% of initial efficiency (T80) for nearly 400 hours at 85°C.
• Outstanding operational durability was observed, with devices sustaining ~50% of initial efficiency after 900 hours under ISOS-L-3 conditions, outperforming all-organic systems.

Conclusions:

• Copper(I) thiocyanate (CuSCN) effectively functions as a multifunctional donor and hole transport layer in organic photovoltaics.
• CuSCN incorporation significantly enhances device thermal stability and operational durability compared to conventional organic materials.
• This study highlights the potential of CuSCN for developing efficient, stable, and industrially relevant organic photovoltaic technologies.