Silicon and zinc telluride nanoparticles synthesized by low energy density pulsed laser ablation into ambient gases
- Solid State Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6056 (United States)
- Life Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6123 (United States)
- Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6376 (United States)
The size distributions of Si and ZnTe nanoparticles produced by low energy density ArF (193 nm) pulsed laser ablation into ambient gases were measured as a function of the gas pressure, {ital P}, and target-substrate separation, D{sub ts}. For both Si and ZnTe, the largest nanoparticles were found closest to the ablation target, and the mean nanoparticle size {ital decreased} with increasing D{sub ts}. For Si ablation into He, the mean nanoparticle diameter did not increase monotonically with gas pressure but reached a maximum near Pthinsp=thinsp6 Torr. High resolution Z-contrast transmission electron microscopy and energy loss spectroscopy revealed that ZnTe nanoparticles consist of a crystalline core surrounded by an amorphous ZnO shell; growth defects and surface steps are clearly visible in the crystalline core. A pronounced narrowing of the ZnTe nanocrystal size distribution with increasing D{sub ts} also was found. The results demonstrate that the size of laser-ablated nanoparticles can be controlled by varying the molecular weight and pressure of an ambient gas and that nanometer-scale particles can be synthesized. Larger aggregates of both ZnTe and Si having a {open_quotes}flakelike{close_quotes} or {open_quotes}weblike{close_quotes} structure were formed at the higher ambient gas pressures; for ZnTe these appear to be open agglomerates of much smaller ({approximately}10 nm) particles. {copyright} {ital 1999 Materials Research Society.}
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 341730
- Journal Information:
- Journal of Materials Research, Vol. 14, Issue 2; Other Information: PBD: Feb 1999
- Country of Publication:
- United States
- Language:
- English
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