Enabling full-scale grain boundary mitigation in polycrystalline perovskite solids

Area of Science:

• Materials Science
• Photovoltaics
• Nanotechnology

Background:

• Polycrystalline perovskites contain numerous interaggregate and intra-aggregate grain boundaries (GBs).
• Both types of GBs negatively impact the performance of perovskite solar cells (PSCs).
• Effective mitigation strategies for intra-aggregate GBs are crucial for improving PSCs.

Purpose of the Study:

• To achieve full-scale mitigation of grain boundaries (GBs) in perovskite films, from nanoscale intra-aggregate to submicron-scale interaggregate.
• To enhance the photovoltaic performance and long-term stability of perovskite solar cells (PSCs).
• To explore a novel approach for fabricating high-quality solution-processed polycrystalline perovskites.

Main Methods:

• Modulating perovskite crystallization kinetics using a designed brominated arylamine trimer.
• Applying the strategy to mesostructured perovskite solar cells (PSCs).
• Testing the versatility of the strategy across different PSC categories.

Main Results:

• Successfully mitigated both intra-aggregate and interaggregate GBs in perovskite films.
• Achieved reduced nonradiative recombination in the optimized perovskite films.
• Demonstrated substantially enhanced device efficiency and long-term stability (under illumination, humidity, and heat stress) in mesostructured PSCs.

Conclusions:

• The developed brominated arylamine trimer effectively mitigates GBs across multiple scales.
• This strategy offers a new perspective for fundamental nanoscale studies of perovskites.
• Opens a viable route for producing high-quality solution-processed polycrystalline perovskites for advanced optoelectronic devices.