Efficient and Stable CuSCN-based Perovskite Solar Cells Achieved by Interfacial Engineering with Amidinothiourea

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Cuprous thiocyanate (CuSCN) is a promising inorganic hole-transport material for perovskite solar cells (PSCs).
• Degradation at the perovskite/CuSCN interface, caused by polar solvents and impurities, limits device efficiency and stability.
• Existing materials face challenges in achieving both high performance and operational longevity in PSCs.

Purpose of the Study:

• To introduce amidinothiourea (ASU) as an intermediate layer to mitigate interfacial degradation in PSCs.
• To enhance the power conversion efficiency (PCE) and operational stability of PSCs.
• To explore a universal fabrication approach for efficient and stable PSCs.

Main Methods:

• Interfacial engineering using amidinothiourea (ASU) as a buffer layer between perovskite and CuSCN.
• Characterization of ASU-modified perovskite films to confirm defect passivation via chemical bonding.
• Fabrication and testing of PSCs with gold and carbon-tape electrodes.

Main Results:

• ASU effectively passivates trap-induced defects in perovskites through strong chemical bonding.
• The ASU interlayer reduces the potential barrier at the perovskite/CuSCN interface.
• ASU-treated PSCs with gold electrodes achieved an improved PCE from 16.36% to 18.03%.
• Devices maintained over 90% of their initial efficiency after 1800 hours of ambient air storage.
• ASU demonstrated potential for fabricating low-cost, stable carbon-based PSCs.

Conclusions:

• Amidinothiourea (ASU) serves as an effective interfacial layer for enhancing the efficiency and stability of perovskite solar cells.
• The ASU approach offers a universal strategy for fabricating high-performance and durable PSCs across different device architectures.
• This work paves the way for more robust and cost-effective perovskite solar cell technologies.