Experimental Determination of the Fluorescence Quantum Yield of Semiconductor Nanocrystals

Abstract

Many studies have considered the luminescence of colloidal II–VI nanocrystals, both in solution at a collective scale and at an individual scale by confocal microscopy. The quantum yield is an important figure of merit for the optical quality of a fluorophore. We detail here a simple method to determine the quantum yield of nanocrystals in solution as a function of the absorption. For this purpose, we choose rhodamine 101 as a reference dye to measure the nanocrystal fluorescence quantum yield. The influence of the concentration on quantum yield is therefore studied for both the reference and the solutions of nanocrystals and is found to be critical for the acuity of the method. Different types of nanocrystals are studied to illustrate different quantum yield evolutions with the concentration.

Impact of reaction variables and PEI/l-cysteine ratio on the optical properties and cytocompatibility of cationic Ag2S quantum dots as NIR bio-imaging probes

“…The ratio of the slope of these plots with the refractive index of water and MeOH based on eqn (2) gave the QY of the prepared QDs. 31,32…”

Synthesis and Optical Properties of Water-Soluble CdTe:Zn2+ Quantum Dots Prepared by the One-Pot Approach

“…29 To aid in understanding the structure and optical properties relationship, we have performed steady-state absorption and emission spectroscopies, along with the evolving factor analysis/multivariate curve resolution alternating least squares (EFA/MCR-ALS) method. 30,31 Through this methodology, we have investigated the optical features, such as steady-state absorption and emission, fluorescence quantum yield (FQY) and size dispersion as a function of synthesis time. Our results pointed out that with the incorporation of Zn 2+ ions in CdTe:Zn 2+ QDs the QD predominant diameter in the ensemble decreases and their size dispersion concomitantly increases.…”

Preparation and Characterization of Spion-CDs as a Multifunctional Fluorescence/Magnetic Resonance Nanoparticle

“…[10][11] Moreover, the crystallite size was calculated ~22 nm using the Quantum yield (QY), defined as the ratio of the number of emitted photons to the number of absorbed photons per time unit, is a significant parameter to characterize PL. 13 The QY of the SPION-CDs was estimated to be 2.4%. A value of QY, over the range of 1 to 5%, is sufficient for celllabeling studies.…”