Multifunctional Conjugated Ligand Engineering for Stable and Efficient Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Surface passivation is crucial for enhancing perovskite solar cell (PSC) efficiency and stability.
• Reducing interface charge recombination without hindering charge extraction is a key challenge in PSC development.

Purpose of the Study:

• To introduce a novel multifunctional semiconducting organic ammonium cationic interface modifier for PSCs.
• To investigate the effects of this modifier on interface charge dynamics, energy level alignment, and device stability.

Main Methods:

• Insertion of a conjugated organic ammonium cation between the perovskite layer and hole-transporting layer.
• Characterization of the modified interface and device performance using power conversion efficiency (PCE) measurements and stability tests.

Main Results:

• The organic cation efficiently extracts holes from perovskite and reduces non-radiative recombination.
• Improved energy level alignment and interface stabilization were observed.
• Achieved a PCE of 22.06% in triple-cation mixed-halide PSCs, an improvement from 19.94%.
• Demonstrated suppressed ion migration and halide phase segregation, leading to enhanced operational stability.

Conclusions:

• The developed organic ammonium cation serves as an effective interface modifier for PSCs.
• This strategy offers a practical approach to interface engineering, significantly improving both efficiency and long-term stability of perovskite solar cells.