Thermal effects in the Raman scattering of vertically-aligned silicon nanowire arrays as investigated by fluence-dependent measurements

  • Mylenne Manrique Materials Science and Engineering Program, University of the Philippines Diliman
  • Horace Andrew Husay National Institute of Physics, University of the Philippines Diliman
  • Arnel Salvador National Institute of Physics, University of the Philippines Diliman
  • Elmer Estacio National Institute of Physics, University of the Philippines Diliman
  • Armando Somintac National Institute of Physics, University of the Philippines Diliman

Abstract

We report on the thermal effects on the Raman scattering of vertically-aligned silicon nanowires (Si NWs) as investigated by fluence-dependent micro-Raman spectroscopy. The Si NWs were grown on p-type Si(100) substrates through electroless metal-assisted chemical etching using an electrolyte composed of hydrofluoric acid and silver nitrate. The Si NWs have a nominal length of 10 μm and nominal width of 100 nm. Fluence-dependent measurements showed that at low laser fluence, the Si NWs exhibit bulk-like features as shown by the 519 cm-1 peak associated with the degenerate longitudinal/transverse optical phonon (LTO) mode. A second broad and downshifted peak at 488-510 cm-1 emerged at high fluences due to the Raman scattering from the array of laser-heated Si NWs. The presence of the two peaks indicated the formation of a thermal gradient across the NWs. The temperature of the Si NWs at the beam spot was also measured through fluence-dependent measurements. The results suggest that Raman spectroscopy is a viable technique to analyze the thermal properties of a material.

Published
2019-05-21
How to Cite
[1]
M. Manrique, H. A. Husay, A. Salvador, E. Estacio, and A. Somintac. Thermal effects in the Raman scattering of vertically-aligned silicon nanowire arrays as investigated by fluence-dependent measurements, Proceedings of the Samahang Pisika ng Pilipinas 37, SPP-2019-PA-28 (2019). URL: https://paperview.spp-online.org/proceedings/article/view/SPP-2019-PA-28.