Synthesis of CdTe colloidal quantum dots (QDs) in water

Abstract

The comparison of growth processes and fluorescent properties of CdTe semiconductor quantum dots (QDs) that are synthesized in water with different modifiers are discussed in this paper. The samples are characterized through ultraviolet-visible spectra (UV-Vis), photoluminescence spectra (PL) and zeta potential. The results show that when the reaction time is prolonged for the same modifier, the ultraviolet absorption peak and fluorescent emission peak present obvious red shifts and the diameters of the QDs continuously increase. With the same reaction time but different modifiers, QDs with different diameters can be gained. The average full width at half maximum of the photoluminescence spectra is about 50 nm which shows that the monodispersity is quite good. Under the best reaction conditions, the highest quantum yield (QY) can be attained by using thioglycollic acid (TGA) as modifier when the reaction time is 240 min. The zeta potential is influenced by the modifier and pH.

References

1. Chan W Nie S Quantum dot bioconjugates forultrasensitive nonisotopic detectionScience 1998 281(5385)2 0162 018. doi:10.1126/science.281.5385.2016
2. Bruchez M Moronne M Gin P Weiss S Alivisatos A P Semiconductor nanocrystalsas fluorescent biological labelsScience 1998 281(5385)2 0132 016. doi:10.1126/science.281.5385.2013
3. Alivisatos A P Perspectiveson the physical chemistry of semiconductor nanocrystalsJournal of Physics Chemistry 1996 100(31) 1322613239. doi:10.1021/jp9535506
4. Colvin V L Schlamp M C Alivisatos A P Light-emitting diodes made from Cadmium Selenide nanocrystalsand a semiconducting polymerNature 1994 370354357. doi:10.1038/370354a0
5. Klimov V I Mikhailovsky A A Xu S Malko A Hollingsworth J A Leatherdale C A Eisler H J Bawendi M G Optical gain and stimulated emission innanocrystal quantum dotsScience 2000 290(5490)314317. doi:10.1126/science.290.5490.314
6. Brus L Electronicwave functions in semiconductor clusters: experiment and theoryJournal of Physics Chemistry 1986 90(12)25552560. doi:10.1021/j100403a003
7. Meng L Song Z X Application of quantum dotsin biomedicineBiochemistry and Biophysicsdevelopment 2004 31(2)185187
8. Santra S Yang H Holloway P H Stanley J T Mericle R A Synthesis of water-dispersible fluorescent,radio-opaque, and paramagnetic CdS: Mn/ZnS quantum dots: A multifunctionalprobe for bioimagingJournal of AmericalChemical Society 2005 127(6)16561657. doi:10.1021/ja0464140