Berlin 2024 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 1: Nitrides: Preparation and characterization I
HL 1.9: Vortrag
Montag, 18. März 2024, 12:00–12:15, EW 015
Multiphonon Raman scattering in rocksalt ScN — •Stefan Wolf1, Jona Grümbel1, Yuichi Oshima2, Christopher Lüttich1, Florian Hörich1, Armin Dadgar1, Martin Feneberg1, and Rüdiger Goldhahn1 — 1Otto-von-Guericke-Universität, Universitätsplatz 2, 39106, Magdeburg — 2Research Center for Electronic and Optical Materials, National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
We investigate rocksalt ScN films with different free carrier concentration using Raman spectroscopy. Two different sets of samples were used for our measurements: (I) ca. 300nm thick ScN grown by sputter epitaxy and (II) 0.4 µ m up to 40 µ m thick ScN grown by HVPE. The HVPE grown ScN exhibits a very good crystalline structure, with carrier concentration varying between 1018cm−3 and 1020cm−3, while for ScN grown by sputter epitaxy, the carrier concentrations even reach 1021cm−3 or more. We obtain detailed information about the impact of free carriers on coupled optical phonon-plasmon (LPP) modes up to a scattering order of nLPP=3.
The observed frequency shift of the first and second order LPP modes with respect to the carrier concentration shows an overdamped behaviour, indicating strong electron-electron interaction. As expected, transverse optical phonon modes show no significant frequency shift over the whole carrier concentration range. Correct assignment of multiphonon lines and possible future steps in understanding their behaviour will be discussed.
Keywords: Scandium Nitride; Raman spectroscopy; Optical Properties; New Materials