Photoluminescence of (Zn, Pb, Mn)S Quantum Dots in Polyacrylate Matrix

• Published in: Semiconductors (Woodbury, N.Y.) N.Y.), 2020-05, Vol.54 (5), p.511-517
• Main Authors: Isaeva, A. A., Smagin, V. P.
• Format: Article
• Language: English
• Subjects: Acrylic resins; Composite materials; Conduction bands; Crystal defects; Crystal structure; Crystals; Energy transfer; Excitation; Low-Dimensional Systems; Magnetic Materials; Magnetism; Manganese ions; Methyl methacrylate; Photoluminescence; Physics; Physics and Astronomy; Polymerization; Polymethyl methacrylate; Quantum dots; Quantum Phenomena; Radiation; Semiconductor Structures; Structure; Thickness; Zinc sulfide
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S106378262005005X

Solutions of (Zn, Pb, Mn)S quantum dots with different molar ratios between cations are produced by colloidal synthesis in a methyl methacrylate (MMA) medium. By the thermal polymerization of MMA in a block, the colloidal solutions are converted into the vitreous state. The optical transparency of the poly(MMA)/(Zn, Pb, Mn)S composites at the wavelengths >500 nm reaches 90% at a thickness of the absorbing layer up to 5 mm. The photoluminescence of the composites in the spectral range 400–480 nm is defined by the recombination of electrons at the levels of defects of the ZnS crystal structure, and photoluminescence in the range 520–620 nm by the 4 T 1 → 6 A 1 electronic transition in Mn 2+ ions. Photoluminescence excitation is a result of interband transitions in ZnS, with energy transfer from the conduction band of ZnS to the levels of Mn 2+ ions. The luminescence spectrum depends on the molar ratio between Mn 2+ and Pb 2+ ions, the order of introduction of substances into the reaction mixture, and the excitation-radiation wavelength.