Tunable KLa(MoO4)2:Eu3+@CDs composite materials for white LED and multi-mode information encryption technology

The composite of biocompatible carbon dots (CDs) and lanthanide-based luminescent materials have high research value as a promising multifunctional material, which are ideally suited to information encryption and white LED. However, the aggregation-induced quenching of CDs in the solid state still troubles the synthesis of CDs with other solid luminescent materials. Herein, a facile strategy to fabricate polychromatic nanoplatform KLa(MoO 4 ) 2 : Eu 3+ @CDs by encapsulating CDs on the surface of KLM: Eu 3+ with silicon shell is reported, in which the aggregation-induced quenching of CDs is avoided. Due to the overlapping of Eu-O charge transfer band with CDs excitation band, the red luminescence of Eu 3+ ions and the blue fluorescence of can be emitted simultaneously under 395 nm excitation. By changing the proportion of KLa(MoO 4 ) 2 : Eu 3+ in KLa(MoO 4 ) 2 : Eu 3+ @CDs, the mixture can emit "warm", "neutral", and "cold" white light, which can realize people's demand for indoor lighting requirements. Furthermore, a multi-mode information encryption by selectively triggering the luminescence of CDs or Eu 3+ ions is also designed. All the results suggest that KLa(MoO 4 ) 2 : Eu 3+ @CDs have excellent luminescence properties that can be further investigated and applied in the field of white LEDs and information encryption.