CdTe Quantum Dots/Layered Double Hydroxide Ultrathin Films with Multicolor Light Emission via Layer‐by‐Layer Assembly

Quantum dots (QDs) luminescent films have broad applications in optoelectronics, solid‐state light‐emitting diodes (LEDs), and optical devices. This work reports the fabrication of multicolor‐light‐emitting ultrathin films (UTFs) with 2D architecture based on CdTe QDs and MgAl layered double hydroxide (LDH) nanosheets via the layer‐by‐layer deposition technique. The hybrid UTFs possess periodic layered structure, which is verified by X‐ray diffraction. Tunable light emission in the red‐green region is obtained by changing the particle size of QDs (CdTe‐535 QDs and CdTe‐635 QDs with green and red emision respectively), assembly cycle number, and sequence. Moreover, energy transfer between CdTe‐535 QDs and CdTe‐635 QDs occurs based on the fluorescence resonance energy transfer (FRET), which greatly enhances the fluorescence efficiency of CdTe‐635 QDs. In addition, a theoretical study based on the Förster theory and molecular dynamics (MD) simulations demonstrates that CdTe QDs/LDH UTFs exhibit superior capability of energy transfer owing to the ordered dispersion of QDs in the 2D LDH matrix, which agrees well with the experimental results. Therefore, this provides a facile approach for the design and fabrication of inorganic‐inorganic luminescent UTFs with largely enhanced luminescence efficiency as well as stability, which can be potentially applied in multicolor optical and optoelectronic devices.