Interfacial Modification via a 1,4-Butanediamine-Based 2D Capping Layer for Perovskite Solar Cells with Enhanced...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Organic-inorganic perovskites suffer from instability due to oxygen, moisture, and defects.
• Two-dimensional (2D) perovskites can enhance the stability and efficiency of three-dimensional (3D) perovskites.
• Surface and grain boundary trap sites limit the performance of 3D perovskites.

Purpose of the Study:

• To improve the photovoltaic efficiency and environmental stability of 3D perovskite solar cells (PSCs).
• To investigate the passivation effects of 2D perovskite capping layers on 3D perovskites.
• To explore the use of 1,4-butanediammonium diiodide (BDADI) for constructing 3D/2D stacking PSCs.

Main Methods:

• Fabrication of 3D/2D stacking perovskite solar cells using BDADI.
• Passivation of surface defects in 3D perovskites with 2D Dion-Jacobson (DJ) phase perovskites.
• Characterization of carrier lifetime, energy level alignment, charge extraction, and water resistance.

Main Results:

• The 2D DJ capping layer effectively passivates surface defects and suppresses nonradiative recombination.
• Carrier lifetime is significantly increased due to defect passivation.
• The hydrophobic nature of the capping layer enhances water resistance of the PSCs.
• Regulated energy level alignment improves charge extraction and transport.

Conclusions:

• The developed 3D/2D stacking PSCs achieve a high energy conversion efficiency of 20.32%.
• The integration of 2D perovskites provides enhanced long-term stability and improved performance.
• BDADI is a promising material for creating stable and efficient perovskite solar cells.