Researchers develop cold-injection method for near-perfect perovskite nanocrystals

A new method makes better perovskite nanocrystals

Researchers have developed a new "cold-injection" method to synthesize high-quality colloidal perovskite nanocrystals (PeNCs). The technique solves key problems with previous industrial-scale production methods.

It enables the creation of PeNCs with a near-perfect photoluminescence quantum yield (PLQY) of ~100%. The resulting crystals are also more stable and emit a pure green light.

The problems with old production methods

For years, two main techniques were used to make these nanocrystals. The first is the hot-injection method, which requires high temperatures, an inert gas environment, and rapid cooling.

These requirements raise significant safety and cost concerns for large-scale manufacturing. The second common technique is room-temperature ligand-assisted reprecipitation.

While simpler, this method suffers from limited productivity when scaled up, making it inefficient for industrial use.

How the cold-injection method works

The new approach is based on a pseudo-emulsion process. Scientists inject a precursor solution at a temperature below 4 °C into the system.

At this cold temperature, fully coordinated plumbates assemble out of the pseudo-emulsion with the help of a demulsifier. This slow, cold-assisted assembly of polybromide plumbates is the key to the method's success.

It is essential for suppressing defects in the crystal structure. This defect suppression is what leads to the high PLQY and stability.

The results enable massive scale-up

The method has proven to be highly scalable in testing. Researchers successfully demonstrated synthesis at a 20-liter scale while maintaining the near-unity PLQY.

This represents a massive batch weight compared to previous techniques. The reproducibility and stability of the crystals made this way are significantly enhanced.

The primary output is a stable, pure-green-emitting PeNC. The consistent quality at large volume is a major breakthrough for potential manufacturing.

Potential for displays and lighting

The findings represent a substantial advancement in the synthesis of high-quality PeNCs. The combination of high yield, stability, and scalability opens new commercial doors.

The most immediate applications are in the display and lighting industries. These sectors require efficient, pure-color emitters that can be produced reliably in large quantities.

This new cold-injection method based on pseudo-emulsion directly addresses the historical bottlenecks that have prevented wider adoption of PeNC technology.