Quantum Dots

Quantum dots (QDs) represent the latest generation of hybrid inorganic-organic nanomaterials. They form a triad of inorganic nanotechnology, organic semiconductor technology and solution-based processability. The emission properties of these inorganic, luminescent nanoparticles are controlled by the particle size. Fraunhofer IAP has developed several procedures for the synthesis and modification of QDs to provide very stable indium phosphide (InP) QDs covering a wide spectral range from green to red with a high quantum yield, low Full Width at Half Maximum (FWHM) and high stability in organic solvents and in polymer materials or resists. Developing the high-performance QD-LEDs based on InP-based QDs is quite important to bring QD-LEDs into the future display market. The Fraunhofer IAP investigated the performance of inverted QD-LEDs fabricated with synthesized multi-shell InP/ZnSe/ZnS QDs and ZnO nanoparticles as well. The results show that InP/ZnSe/ZnS QDs is the most promising candidate for the Cd-free QD-LEDs. The investigated QD-LEDs match the performance of CD-based QD-LEDs with luminance values higher than 25.000 cd/m 2.