# Color‐Tunable Organic Nano‐Dots: Synthesis and Applications in Color Conversion and Security Inks

## TL;DR

Researchers created water-based organic nanodots that can emit various colors, including white light, and are useful for displays and security inks.

## Contribution

The study introduces a scalable method for making color-tunable organic nanodots with high energy transfer efficiency and color conversion performance.

## Key findings

- CTONDs achieve over 90% energy transfer efficiency in film state due to close packing.
- They show over 60% color conversion efficiency in light-emitting devices with four-month photostability.
- The nanodots are aqueous-processable and suitable for eco-friendly displays and security inks.

## Abstract

This study explores the synthesis of water‐based color‐tunable organic nanodots (CTONDs) capable of emitting multiple colors, including white light, by adjusting the molar ratio of blue, green, and red emissive fluorophores in the particles. Spectroscopic analyses reveal that the emissions are due to Forster resonance energy transfer (FRET) between the energy donor and acceptor nanoparticles. The energy transfer efficiencies are high, reaching over 90% in the film state due to the close packing of NDs while in their film state. Various molar ratios produced different colors in both liquid dispersions and in the solid state. These CTONDs demonstrate over 60% color conversion efficiency (CCE) when applied as color conversion layers (CCLs) in light‐emitting devices, maintaining photostability for over four months under ambient conditions. Additionally, their aqueous processability and multicolor tunability make them attractive for environmentally friendly display technologies, flexible optoelectronics, and anti‐counterfeiting applications such as security inks. This work offers a scalable and sustainable approach to fabricating tunable, solution‐processed fluorescent organic nanomaterials and underscores their promise as a versatile platform for next‐generation photonic and optoelectronic applications.

Color‐tunable organic nanodots prepared via micelle‐assisted self‐assembly exhibit efficient Förster energy transfer and multicolor emission, including white light. These aqueous nanodots demonstrate high color conversion efficiency, long‐term stability, and compatibility with solid films and paper substrates. Their tunability, processability, and performance make them promising candidates for eco‐friendly display technologies and anticounterfeiting fluorescent inks.