Composition and crystallization process optimization of multifunctional CdS quantum dots embedded glass with color-tunable and high-efficiency photoluminescence

Quantum dot (QD) materials, characterized as quasi-zero-dimensional nanocrystals, have garnered considerable attention due to their distinct optical properties arising from quantum size confinement effects, distinguishing them from bulk materials. Despite these advantages, challenges persist in achieving long-term stability and high luminescent efficiency. Addressing these issues, CdS QDs were successfully precipitated in a silicate glass matrix through a combination of melt-quenching and controlled crystallization techniques. Structural and morphological analyses confirmed the in-situ precipitation of CdS QDs with sizes < 20 nm within the glass matrix. Under 395 nm light excitation, the light color emitted from the CdS QD glass transitions from yellow to red, exhibiting an impressive internal quantum efficiency (IQE) of 67.14 %, notably surpassing other CdS QD glasses. Furthermore, the QD glass retained 85 % of its luminescent intensity at room temperature even when exposed to a high temperature of 150( degrees)C, demonstrating superior thermal stability compared to colloidal QDs. As a proof of concept, a full-spectrum luminescent white-light emitting diode (W-LED) device was encapsulated using the UV LED chip, CdS QD glass, BaMgAl10O17 :Eu 2+ blue phosphor, and Ba2SiO4 :Eu (2+ )green phosphor. This device exhibited suitable chromaticity coordinates of (0.3473, 0.3750), a correlated color temperature of 4996 K, and an impressive color rendering index of 92.5. Additionally, the X-ray imaging performance of CdS QD glass was assessed using a customized optical system, underscoring its promising potential in scintillation imaging applications such as non-destructive testing. In summary, the compositional optimization and controllable crystallization techniques employed in this study offer valuable insights for developing QD glasses with exceptional properties. The substantial potential benefits of CdS QD glasses are convincingly demonstrated through physical demonstration, particularly in the realms of W-LED lighting and X-ray scintillation imaging.