Hybrid ZnO-Based Nanoconjugate for Efficient and Sustainable White Light Generation

Developing new ways of generating white light is of paramount importance for the design of the next generation of smart, energy-efficient lighting sources. Here we report tunable white light emission of hybrid organic–inorganic nanostructures based on colloidal ZnO nanocrystals conjugated with organic fluorophores. These materials act as single nanophosphors owing to the distance-dependent energy transfer between the two components. The defect-based size-tunable ZnO nanocrystal blue-green emission coupled with complementary color emission from different fluorophores allows for the generation of white light with targeted chromaticity, color temperature, and color rendering index. We further show that silane layer-protected nanoconjugates result in increased stability of white light emission over a long period of time. The results of this work demonstrate an inexpensive, green, and sustainable approach to general solid-state lighting, without the use of rare earth or heavy metals. Colloidal form of the reported hybrid nanoconjugates allows for their further functionalization or incorporation into light-emitting devices. More broadly, size dependence of the electronic structure of native defects in transparent metal oxide nanocrystals and their electronic coupling with conjugated organic species could also represent a vehicle for introducing and manipulating new properties in these hybrid nanostructures.