Photoluminescent (CdSe)ZnS quantum dot–polymethylmethacrylate polymer composite thin films in the visible spectral range

Abstract

We synthesized (CdSe)ZnS quantum dot (QD)–polymethylmethacrylate (PMMA) polymer composite and fabricated QD–polymer composite films. We produced the CdSe and (CdSe)ZnS QDs by direct colloidal chemical synthesis and the surface-passivation method—an overcoating of the dots with a larger-bandgap material. PMMA is transparent in the visible spectral range and was chosen as the embedding matrix for QDs. A 28%(wt/wt) of PMMA in MMA was the most appropriate concentration to produce a film of good quality and maximize the solubility of quantum dots without phase separation of the QDs from the matrix. We fabricated green or red light emitting (CdSe)ZnS QD–PMMA polymer composite film by combining the green or red light emitting (CdSe)ZnS dots with PMMA of high optical transparency in the visible region and spin-coating the composite solution. The fabricated green light emitting (CdSe)ZnS–PMMA composite film had a good quantum yield of 40% and a narrow emission band at 543 nm with a full width at half maximum of ∼35 nm. A white light emitting device can be fabricated by combining our green/red light emitting QD–polymer composites with a blue light emitting LED as an excitation source. Our QD–polymer composites can be applied to flexible coloured filters, large-area coloured wall-papers and full colour displays.

Temperature Sensor Based on Colloidal Quantum Dots–PMMA Nanocomposite Waveguides

“…Walker et al first characterized the temperature response of the photo-luminescence (PL) of colloidal QDs immobilized inside a polylaurylmethacrylate (PLMA) matrix [10] proving the suitability of QDs as temperature references for PL-based sensing applications. Other authors have also reported the use of different host polymers such as polystyrene (PS) [11] or polymethylmethacrylate (PMMA) [12] to embed QDs, and even coupling the light with the aid of optical fibers [13]. All these works use the PL of QDs as the sensing parameter, but none of them integrate the PL response into an optical waveguide, which is the key step to develop a temperature sensor into a photonic device.…”

Functionalisation of Colloidal Transition Metal Sulphides Nanocrystals: A Fascinating and Challenging Playground for the Chemist

“…plastics was investigated [391][392][393] A further elegant route to surface-functionalized ZnS nanoparticles (NPs) to be embedded in polymer matrix was based on a facile ligand exchange approach of mercaptoethanol with 5-(2-methacryloylethyloxymethyl)-8-quinolinol (MQ) [278]. By exploiting in situ bulk polymerization, the functionalised MQ-ZnS NPs were successfully incorporated into the polymer matrix to fabricate transparent bulk nanocomposites with good thermal stability and processability.…”

“…In the literature are however reported several examples of stable derivatisation of ZnS colloids, and hereafter some of the most meaningful ones are reported. Recently, the incorporation of ZnS:Mn NPs into polymeric matrix (polyacrylic acid and polymethylmethacrylate) to convey luminescent properties to plastics was investigated [391][392][393], although no specific functions by the polymers were demonstrated to enhance the interactions with the NPs. Alternatively, semiconductor nanocrystals (entirely or partially constituted by sulphides) were successfully incorporated into polymeric matrices [394] or derivatised with oleic acid and hexadecyl-trimethylammonium bromide to allow their dispersion in organic phases.…”

Diseño de técnicas de interrogación y sensores en fibra para el sector de la construcción

“…Walker et al first characterized the temperature response of the photo-luminescence (PL) of colloidal QDs immobilized inside a polylaurylmethacrylate (PLMA) matrix [10] proving the suitability of QDs as temperature references for PL-based sensing applications. Other authors have also reported the use of different host polymers such as polystyrene (PS) [11] or polymethylmethacrylate (PMMA) [12] to embed QDs, and even coupling the light with the aid of optical fibers [13]. All these works use the PL of QDs as the sensing parameter, but none of them integrate the PL response into an optical waveguide, which is the key step to develop a temperature sensor into a photonic device.…”

“…Walker et al caracterizaron por primera vez la respuesta con la temperatura de la fotoluminiscencia (en adelante PL, Photoluminescence) de QD coloidales inmovilizados dentro de una matriz de polilauril metacrilato (PLMA) [Walker03], demostrando la idoneidad de los QD como sensores de temperatura para aplicaciones de sensado basadas en PL. Otros autores también han informado del uso de diferentes polímeros como material base tales como poliestireno (PS) [Valerini05], o polimetil metacrilato (PMMA) [Song07] para embeber los QD, e incluso se ha utilizado la ayuda de fibra óptica para llevar a cabo el acoplo de luz [Jorge05]. Todos estos trabajos usan la PL de los QD como el parámetro de sensado, pero ninguno de ellos integra la respuesta de PL en una guía de ondas óptica, que es el paso clave para desarrollar un sensor de temperatura en de un dispositivo fotónico.…”