2D or Not 2D? Impact of Bulky Cation Deposition Method on Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Three-dimensional/two-dimensional (3D/2D) heterojunctions are effective in standard perovskite solar cells.
• Their application in inverted (p-i-n) structures is limited by 2D phase thickness requirements for electron extraction.

Purpose of the Study:

• Investigate the benefits of 3D/2D dimensional engineering in inverted perovskite solar cells.
• Evaluate the impact of deposition methods on 2D phase formation and device performance.

Main Methods:

• Introduced 4-chlorophenethylammonium iodide (Cl-PEAI) to triple cation perovskite films.
• Employed two deposition methods: interlayer and antisolvent approach.
• Utilized low-energy cathodoluminescence for 2D phase detection.

Main Results:

• The interlayer method formed detectable 2D phases (n=1, n=2).
• The antisolvent method resulted in surface and grain boundary passivation without significant 2D phase formation.
• Device performance improved with passivation, but not with 2D phase formation.

Conclusions:

• Deposition method critically influences 2D layer formation over 3D perovskites in inverted architectures.
• 2D phase formation is not universally beneficial for inverted perovskite solar cell performance.
• Surface passivation is a more effective strategy for improving inverted device efficiency.