Journal
JOURNAL OF PHYSICAL CHEMISTRY C
Volume 113, Issue 16, Pages 6497-6504Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp811263c
Keywords
-
Funding
- Natural Sciences and Engineering Research Council of Canada
- Fonds de la recherche sur la nature et les technologies
Ask authors/readers for more resources
We examine the effect of reaction time, temperature, molar ratio of precursors, capping ligands, and aging on the growth of PbS quantum dots in a nonviscous, solventless, mild-constant-temperature system with PbCl2 and S as precursors. It is found in our system that Ostwald ripening leads to bimodal photoluminescence corresponding to the bimodal size distribution of PbS quantum dots, as evidenced by transmission electron microscopy, in contrast to commonly reported single-peak broadening due to Ostwald ripening. The evolution of photoluminescence spectra mediated by Ostwald ripening is strongly affected by reaction parameters. Under certain conditions, the photoluminescence band exhibits some initial broadening upon the action of Ostwald ripening and then gradually transforms into a bimodal structure. In other cases, bimodal peaks rapidly appear as early as 1 min after the reaction starts. Moreover, it is found that the addition of an additional ligand trioctylphosphine immediately initiates the bimodal photoluminescence, which, however, on the basis of photoluminescence spectra characteristics is not thought to be associated with Ostwald ripening. For the bimodal emission structure, aging can greatly enhance the emission peak at shorter wavelength, but it does not affect the emission peak at longer wavelength. Using our simple system, we are able to synthesize PbS quantum dots with a narrow size distribution evidenced by a full width at half-maximum of the photoluminescence peak as low as 58 meV.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available