Full-color-tunable AIE luminogens for 4D code, security patterns, and multicolor LEDs

The regulation of fluorescence color and wavelength of organic luminescent materials is important for their practical applications. However, the aggregation-caused quenching (ACQ) effect in the aggregate state, complex synthesis, sophisticated regulations, and abrupt color transitions of most materials have made such a mission challenging. Here, we develop a color-tunable solid-emitters system based on mechanochromic aggregation-induced emission luminogens (AIEgens). By changing the molecular structure and molecular packing of AIEgens, the wavelength and color of emissions can be adjusted smoothly and easily across the entire visible spectrum. In addition to their reversible, tunable, and highly efficient fluorescence, these AIEgens have the advantage of being difficult to quantify and imitate because of their force response. Taking advantage of these excellent performances, we develop three applications based on the advanced solid optical materials: (1) 4D code, (2) anti-counterfeiting patterns, and (3) full-color light-emitting diodes.