Chelate Multisite Coordination for High-Performance Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Chemical Engineering
• Renewable Energy

Background:

• Interfacial defects, especially nonradiative recombination centers, hinder charge transport and reduce perovskite solar cell (PSC) performance.
• Small molecule doping is a promising strategy for improving film formation, crystal growth, and defect passivation in PSCs.

Purpose of the Study:

• To introduce N,N -ethylenediamine disuccinic acid (EDDS) as a chelating agent for passivating interfacial defects in PSCs.
• To investigate the mechanism of defect passivation and its impact on device performance and stability.

Main Methods:

• Density Functional Theory (DFT) calculations to study coordination bond formation.
• Experimental characterization of film properties and device performance.
• Long-term operational stability testing under continuous illumination.

Main Results:

• EDDS effectively passivates uncoordinated Pb2+ and I- defects via stable Pb-O and I-O coordination bonds.
• Nonradiative recombination is suppressed, leading to prolonged charge carrier lifetimes.
• EDDS-incorporated inverted PSCs achieve a champion power conversion efficiency of 24.57% and retain 90.2% efficiency after 3000 hours.

Conclusions:

• Multisite coordination chemistry using EDDS is highly effective in mitigating interfacial recombination in PSCs.
• EDDS significantly advances the development of highly efficient and stable perovskite photovoltaics.