What is a Convincing Photoluminescence Quantum Yield of Fluorescent Nanocrystals

Abstract

The photoluminescence (PL) quantum yield (QY) is a significant parameter for evaluating the optical properties of fluorescent nanocrystals (NCs). Over the past two decades, different experimental conditions were used for the QY measurement of fluorescent NCs. It makes the reported QY value incomparable in different reference works. Up to now, a definite standard for the QY measurement of fluorescent NCs is still lacking. In this work, NC exciton absorbance in range of 0.01-0.05 is recommended as a new standard condition for the QY measurement of NCs, which is established by consideration of the accuracy of both integrated fluorescent emission and absorbance at excitation wavelength. The measured QY of NCs only convincing in the recommended standard condition. For NCs with a much higher exciton absorbance than the standard condition, their actual PL QY can be obtained by two different ways. First, fluorescent NCs are directly used for the QY measurement. Then the actual QY is available after calibration of the measured apparent QY. Second, fluorescent NCs are diluted to the standard condition before the QY measurement. In this case, the measured QY is the actual QY.

Enhancing Photocurrent Efficiencies by Resonance Energy Transfer in CdTe Quantum Dot Multilayers: Towards Rainbow Solar Cells

“…Table S1 (Supporting Information) summarizes the diameters ( ø ), the emission maxima, the absorption maxima, and the emission quantum yields (QY) in aqueous solution. Importantly, ø s and QYs were determined using previously reported protocols 36–38…”

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“…fluorescence, optical emission) such as QDs. The method is more sensitive if compared to methods depending on photoluminescence which require the use of much higher concentrations for a precise measurement 36 .…”