Silicon and zinc telluride nanoparticles synthesized by low energy density pulsed laser ablation into ambient gases

Journal Article · Mon Feb 01 04:00:00 EST 1999 · Journal of Materials Research

DOI:https://doi.org/10.1557/JMR.1999.0053· OSTI ID:341730

Lowndes, D H; Rouleau, C M; Duscher, G; Pennycook, S J ^[1]; Thundat, T G ^[2]; Kenik, E A ^[3]

---

1. Solid State Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6056 (United States)
2. Life Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6123 (United States)
3. 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 Laboratory
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 341730
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 2 Vol. 14; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
ENERGY BEAM DEPOSITION
MICROSTRUCTURE
PARTICLE SIZE
POWDERS
TELLURIUM COMPOUNDS
ZINC COMPOUNDS
ZINC TELLURIDES