June 08, 2026 -- Scientists from NTU have developed a new type of perovskite nanocrystal that remains bright and stable in water, signifying a major step forward for quantum technologies and bioimaging applications.

Known for their vivid colours and strong brightness, halide perovskite nanocrystals are a type of semiconductor nanocrystal with promising quantum technology and imaging applications. However, they break down quickly when exposed to even the slightest amount of moisture, limiting their use in biological or water-based environments.

Led by Prof Sum Tze Chien, Director of the Institute of Advanced Studies at NTU and Associate Dean (Research) of NTU’s College of Science, the researchers repurposed oleylammonium halide molecules – chemicals normally used to protect nanocrystal surfaces – to drive a process that forms a protective double-layered shell around the nanocrystals in water. This strategy keeps the nanocrystals dispersed and stable while maintaining their brightness.

After the treatment, the nanocrystals maintained high brightness, even at extremely low concentrations, re-emitting 80% of the light they absorbed.

Dr He Huajun, senior research fellow at NTU’s School of Physical & Mathematical Sciences and first author of the work, says the ability to create highly diluted yet bright water-stable perovskite quantum emitters could open up new avenues for sensing and photonics applications in aqueous environments.