In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 1307 ( 2011)
Kurzfassung:
A recurrent problem in the synthesis of hexagonal boron nitride (h-BN) is contamination with oxygen and carbon, leading to possible detrimental effects on optical and electronic properties. Here it is shown that the addition of H 2 to the N 2 /Ar mixture used during the deposition process, clearly suppresses the incorporation of these elements, reducing their combined level below 5 %. The surface morphology, assessed with scanning electron microscopy (SEM), revealed the presence of h-BN nanowalls, i.e. vertically positioned 2D structures consisting out of several h-BN sheets. While Fourier transform infrared (FTIR) spectroscopy revealed the sp 2 nature of the bonds, confirming the hexagonal nature of the nanowalls, the quasi-perfect stoichiometry of the material was evidenced by combining energy dispersive X-ray analysis (EDX) and Rutherford backscattering spectroscopy (RBS). The dimensions and density of these walls are clearly film thickness dependent and cross-sectional TEM images confirmed the increasing level of porosity with film thickness. A dense layer of material is present at the substrate-film interface, which gradually evolves into the 2D nanowall structures.
Materialart:
Online-Ressource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/opl.2011.505
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2011
Permalink