Facet-Dependent Passivation for Efficient Perovskite Solar Cells.

Area of Science:

• Materials Science
• Photovoltaics
• Surface Chemistry

Background:

• Perovskite solar cells (PSCs) face challenges with surface defects impacting performance and stability.
• Understanding surface structure-passivation material interactions is crucial but remains largely unsolved.
• Facet-dependent passivation is a key area for improving PSCs.

Purpose of the Study:

• To elucidate a fundamental principle of surface passivation in perovskite solar cells.
• To investigate the role of crystallographic facets in passivation efficacy.
• To identify novel passivation materials for enhanced device performance.

Main Methods:

• Investigated passivation phenomena on different crystallographic facets of perovskite materials.
• Utilized various post-treatment materials with distinct functionalities.
• Analyzed the relationship between atomic arrangements and passivation layer alignment.
• Identified 2-amidinopyridine hydroiodide as a promising passivation agent.

Main Results:

• Demonstrated a facet-dependent passivation phenomenon in perovskite solar cells.
• Showcased selective passivation occurring on specific crystal facets.
• Achieved a uniform and effective passivation using 2-amidinopyridine hydroiodide on (100) and (111) facets.
• Developed perovskite solar cells with a certified efficiency of 25.10% and improved operational stability.

Conclusions:

• The facet-dependent passivation principle offers a new strategy for optimizing perovskite solar cells.
• This understanding provides insights into previously unidentified passivation mechanisms.
• The findings pave the way for enhanced performance and longevity in perovskite-based optoelectronic devices.