Decoding Charge Recombination and Extraction at Perovskite Interfaces with Transient Photoluminescence

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Understanding charge carrier dynamics at buried interfaces is crucial for optimizing perovskite solar cells (PSCs).
• Interfacial recombination and charge extraction significantly impact device performance.
• Current methods for evaluating buried interfaces are limited.

Purpose of the Study:

• To develop a novel methodology for analyzing charge carrier dynamics at buried perovskite interfaces.
• To compare the performance of self-assembled monolayer (SAM)-based devices with conventional semiconductor thin-film devices.
• To identify the key factors limiting and enhancing PSC performance.

Main Methods:

• Transient photoluminescence spectroscopy combined with a differential equation-based analytical framework.
• Investigating charge extraction and recombination processes at perovskite interfaces.
• Comparing devices utilizing SAMs versus conventional hole transport layers.

Main Results:

• Self-assembled monolayer (SAM)-based devices show superior efficiency due to reduced defect-mediated recombination.
• Hole extraction efficiency of SAMs is lower, especially at low carrier concentrations.
• Mitigation of interfacial defects and Shockley-Read-Hall (SRH) recombination are critical for performance enhancement.

Conclusions:

• Precise regulation of interfacial defects and SRH recombination are more critical than maximizing charge extraction for PSC performance.
• The developed methodology provides a robust framework for interface design and optimization in PSCs.
• The non-contact, high-throughput approach facilitates accelerated material discovery for energy research.