Institut de Chimie, Clermont-Ferrand
During the last decade, the demand in nanophosphors has dramatically increased for addressing the requirements needed for several applications. In particular, nanosized phosphors with efficient optical properties have attracted much attention since they can be used in high-performance displays as well as fluorescent probes in nanomedicine or for specific shaping such as 3D printing with ink-jet techniques. Two distinct approaches can be considered for their design, the bottom-up (assembly from molecules) or the top-down strategies (size reduction to nanoscale).
In this talk, I will illustrate both approaches for synthesizing several types of nanosized phosphors, i.e. inorganic (oxide and fluoride), organic-inorganic hybrids (organic dye encapsulated into silica nanoparticles) and semi-conductor nanocrystals (Quantum Dots or QDs). In particular, the preparation of Y3Al5O12:Ce3+ and NaYF4:Yb3+,Tm3+ nanoparticles and their implementation as respectively yellow-emitting phosphor for LED devices based on microLEDs (mLED) and up-converting phosphor in the infrared range for medical imaging will be discussed. Furthermore, the development of luminescent hybrid nanoparticles composed of fluorescein entrapped into silica matrix by reverse microemulsion method will be presented. Finally, the last part will be devoted to a family of Cd-free QDs, constituted of InP cores coated with a ZnS shell, which are of great interest due to the size dependence of their outstanding optical properties.