Tailoring the energy gap to promote long wavelength emission of nitrogen-doped sulfur quantum dots via dual functional ethylenediamine
The direct conversion of abundant sulfur powder to stable long-wavelength emission sulfur quantum dots (SQDs) is now in the early stage due to the non-soluble property of bulk sulfur powder. To solve this issue, ethylenediamine (EDA) was employed as an effective solvent to disperse sulfur while simu...
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Published in | Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 12; no. 13; pp. 4817 - 4824 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
28.03.2024
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Subjects | |
Online Access | Get full text |
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Summary: | The direct conversion of abundant sulfur powder to stable long-wavelength emission sulfur quantum dots (SQDs) is now in the early stage due to the non-soluble property of bulk sulfur powder. To solve this issue, ethylenediamine (EDA) was employed as an effective solvent to disperse sulfur while simultaneously acts as a nitrogen doping agent to construct green-emitting nitrogen doped sulfur quantum dots (N-SQDs). The pronounced N-SQDs shows a maximum emission wavelength at 526 nm with satisfactory quantum yield reaching up to 25.3%. The N-SQDs even exhibited a red-shifted photoluminescence from blue to green as the concentration increased. Moreover, we proposed a tentative mechanism for the formation of N-SQDs through the cleavage of the sulfur ring in the presence of EDA by sulfur–amine reaction, which then rapidly converted zero-valent sulfur into polysulfide to offer N-SQDs. Comprehensive theoretical calculations suggest that the nitrogen groups contribute to the upshift of the highest occupied molecular orbital energy, reducing the energy gaps of N-SQDs and yield red-shifted wavelength. The EDA even offers an electron donation to the skeleton of SQDs, resulting in an enhanced fluorescence quantum yield. |
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ISSN: | 2050-7526 2050-7534 |
DOI: | 10.1039/D4TC00155A |