Initial Growth of BN on Diamond Substrates: A Theoretical Approach
2010 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, no 26, 11448-11455 p.Article in journal (Refereed) Published
Cubic boron nitride, c-BN, is a very interesting material due to its extreme properties of which some are comparable, or even superior, to diamond. Unfortunately, there are severe problems with the vapor phase synthesis of c-BN, which makes it very important to investigate the possibility for new growth pathways. The choice of substrate has been experimentally found to be decisive for an ideal growth of c-BN. Diamond is a material that has been found to be a good substrate for growth of c-BN directly onto the substrate. By using quantum mechanical density functional theory (DFT) under periodic boundary conditions, the details in the layer-by-layer formation of BN onto diamond (100) has been investigated in the present study. The prerequisites for an initial growth of c-BN (100) have been studied by adding the alternative B and N layers sequentially and calculating the resulting interfacial binding strengths and geometrical structures. For the situation with one monatomic layer on diamond, the interfacial binding energy was calculated to be strongest for nitrogen heteroepitaxially positioned onto diamond (100). The individual atoms in a monatomic B adlayer did, however, not choose corresponding heteroepitaxial positions. When applying a second atomic layer of c-BN, two different models were initially constructed with different structural alignments with respect to the underlying diamond structure. One model was heterostructurally positioned on top of diamond (100), while the other model had the x-axis of the c-BN lattice aligned with the y-axis of the diamond lattice. For the situation with N attached to the diamond substrate, the heteroepitaxial adlayer structure stayed cubic as a result of the geometry optimization, while the other became amorphous-like. Both of these adlayer structures showed large interfacial binding strengths, but the amorphous-like structure became energetically the most stable one. On the contrary, a two-layer BN structure with B attached to the diamond surface did not show the same characteristics. It was only the initial heteroepitaxial BN lattice that resulted in a stable adlayer structure. It stayed cubic after the geometry optimization, with a large interfacial binding strength. The four-layer BN structure on diamond showed similar features.
Place, publisher, year, edition, pages
2010. Vol. 114, no 26, 11448-11455 p.
Research subject Chemistry with specialization in Inorganic Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-136025DOI: 10.1021/jp911924gISI: 000279282200018OAI: oai:DiVA.org:uu-136025DiVA: diva2:376149