Emission amplification by sumanene nanocrystals in an onigiri-type organic-organic assembly

Core-shell assemblies of nanocrystals of sumanene (shell) and sumanenetrione (core) resembling onigiri (filled Japanese rice balls) were fabricated by stepwise reprecipitation. Optical properties of the onigiri-type assemblies showed that emissions from the core sumanenetrione nanocrystals were amplified through energy transfer from the shell sumanene nanocrystals through the nanocrystalline interface.