Mercaptosilane-Passivated CuInS₂ Quantum Dots for Luminescence Thermometry and Luminescent Labels

Abstract

Bright and nontoxic quantum dots (QDs) are highly desirable in a variety of applications, from solid-state devices to luminescent probes in assays. However, the processability of these species is often curbed by their surface chemistry, which limits their dispersibility in selected solvents. This renders a surface modification step often mandatory to make the QDs compatible with the solvent of interest. Here, we present a new synthetic approach to produce CuInS 2 QDs compatible with organic polar solvents and readily usable for the preparation of composite materials. 3-Mercaptopropyl trimethoxysilane (MPTS) was used simultaneously as solvent, sulfur source, and capping agent for the QD synthesis. The synthesized QDs possessed a maximum photoluminescence quantum yield around 6%, reaching approximately 55% after growing a ZnS shell. The partial condensation of MPTS molecules on the surface of QDs was probed by solid-state nuclear magnetic resonance, whose results were used to interpret the interaction of the QDs with different solvents. To prove the versatility of the developed QDs, imparted by the thiolated silane molecules, we prepared via straightforward procedures two nanocomposites of practical interest: (i) silica nanoparticles decorated with QDs and (ii) an inexpensive polymeric film with embedded QDs. We further demonstrate the potential of this composite film as a luminescence thermometer operational over a broad temperature interval, with relative thermal sensitivity above 1% K −1 in the range of biological interest.

Optimization of the electron transport layer in quantum dot light-emitting devices

“…These materials offer structural and compositional flexibility, which can be utilized to control their optical properties. Moreover, some works exhibit 60-90% photoluminescence efficiency of these nanoparticles [11][12][13] . The efficiency of charge transport between layers depends on the alignment of energy levels within a device.…”

Eu3+-doped ratiometric optical thermometers: Experiment and Judd-Ofelt modelling

“…Among these techniques, the luminescence thermometry has gained considerable interest because of its advantages of fast response and applicability in hostile environments and high electromagnetic fields [10]. Luminescence thermal sensing was successfully demonstrated using different types of phosphors including quantum dots, fluorescent dyes and proteins, polymers, metal-organic frameworks, and rare earth or transition metal-doped materials [11][12][13][14][15][16][17][18]. Rare earth-doped phosphors have attracted the most attention as optical thermometers due to their unique spectroscopic properties: narrow emission and excitation lines, long lifetime, large Stokes shift, and diversity of emitting wavelength [19,20].…”

Single Excited Dual Band Luminescent Hybrid Carbon Dots-terbium Chelate Nanothermometer

“…Luminescence-based temperature sensing is outstanding due to its merits of being noninvasive and accurate [25][26][27] . Therefore, in terms of temperature sensing, luminescence studies of organic dyes 28 , lanthanide-based nanomaterials 29,30 , semiconductor nanocrystals [31][32][33][34] , and carbon dots 35,36 have attracted much attention.…”