Temporally resolved laser induced
plasma diagnostics of single crystal silicon - effects of ambient pressure

Cowpe, JS; Astin, JS; Pilkington, RD; Hill, AE

Abstract

Laser-Induced Breakdown Spectroscopy of silicon was performed using a nanosecond pulsed frequency
doubled Nd:YAG (532 nm) laser. The temporal evolution of the laser ablation plumes in air at atmospheric
pressure and at an ambient pressure of ∼10−5 mbar is presented. Electron densities were determined from
the Stark broadening of the Si (I) 288.16 nm emission line. Electron densities in the range of 6.91×1017 to
1.29×1019 cm−3 at atmospheric pressure and 1.68×1017 to 3.02×1019 cm−3 under vacuum were observed.
Electron excitation temperatures were obtained from the line to continuum ratios and yielded temperatures
in the range 7600–18,200 K at atmospheric pressure, and 8020–18,200 K under vacuum. The plasma
morphology is also characterized with respect to time in both pressure regimes.

• Journal Article Type: Article
• Publication Date: Jan 1, 2008
• Deposit Date: Nov 30, 2009
• Publicly Available Date: Apr 5, 2016
• Journal: Spectrochimica Acta Part B Atomic Spectroscopy
• Print ISSN: 0584-8547
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 63
• Pages: 1066-1071
• DOI: https://doi.org/10.1016/j.sab.2008.09.007
• Keywords: LIBS; Laser ablation; Plasma diagnostics; Vacuum; Silicon
• Publisher URL: http://dx.doi.org/10.1016/j.sab.2008.09.007