| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1494002 | Optical Materials | 2014 | 7 Pages |
•Indium phthalocyanine–CdSe/ZnS quantum dots (QDs) nanocomposites (InPc–CdSe/ZnS) of three sizes were synthesized.•The nonlinear absorption (NLA) properties of the nanoconjugates were observed at 532 nm wavelength.•The NLA was found to increase with the size of the CdSe/ZnS QDs attached to the phthalocyanine.
Indium phthalocyanine–CdSe/ZnS quantum dots (QDs) nanocomposites (InPc–CdSe/ZnS) of three sizes (5.57, 8.12 and 8.75 nm) were synthesized according to known procedures. The particle size of the CdSe/ZnS QDs alone are 3.95, 6.02, and 6.66 nm, and are denoted as QD1, QD2 and QD3 respectively. The nonlinear absorption (NLA) properties of the nanoconjugates (InPc–CdSe/ZnS) were investigated with nanosecond laser radiation at 532 nm wavelength. Enhanced NLA properties compared to the InPc alone were observed in the conjugates. The NLA was found to increase with the size of the CdSe/ZnS particles attached to the phthalocyanine. The observed increase was due to the availability of more free-carrier ions in the larger QDs, thus giving rise to the enhanced free-carrier absorption. The measured free-carrier absorption cross-sections (σFCA) are 1.10, 1.65 and 1.95 (×10−19 cm2) for InPc-QD1, InPc-QD2 and InPc-QD3 respectively. The nanoconjugates (InPc–CdSe/ZnS) showed a much lower threshold for optical limiting together with a much lower transmission at high fluences, than the previously reported nanocomposite limiters.
Graphical abstractNonlinear optical behaviour of indium phthalocyanine improved with increase in the size of the attached CdSe/ZnS quantum dots.Figure optionsDownload full-size imageDownload high-quality image (67 K)Download as PowerPoint slide
