Metastable Dion-Jacobson 2D structure enables efficient and stable perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Three-dimensional (3D) organic-inorganic halide perovskite solar cells (PSCs) show promise for efficient solar energy conversion.
• Enhancing charge transport and operational stability in PSCs remains a key challenge for commercialization.

Purpose of the Study:

• To improve the performance of 3D PSCs by employing surface treatment with 2D layered perovskites.
• To investigate the role of a metastable Dion-Jacobson (DJ) 2D perovskite layer in optimizing hole transport and device efficiency.

Main Methods:

• Fabrication of 3D PSCs with a surface treatment of a metastable DJ 2D perovskite.
• Tuning the orientational arrangements of asymmetric bulky organic molecules within the 2D perovskite layer.
• Characterization of charge transport properties and power conversion efficiency (PCE).

Main Results:

• The metastable DJ 2D perovskite surface layer reduced the energy barrier for hole transport, increasing out-of-plane transport rates by 4-5 times.
• A standalone 2D PSC achieved a PCE of 4.9%.
• The PCE of common 3D PSCs was enhanced by 12-16%, reaching up to 24.7% with the 2D surface layer. A triple-cation–mixed-halide PSC retained 90% of its initial PCE after 1000 hours of operation.

Conclusions:

• Surface treatment with a metastable DJ 2D perovskite is an effective strategy to enhance the performance of 3D PSCs.
• The optimized hole transport and improved stability suggest significant potential for scalable perovskite solar technology.
• This approach offers a pathway to higher efficiency and more durable perovskite solar cells.