| 1. |
- Usachov, D., et al.
(författare)
-
Nitrogen-Doped Graphene: Efficient Growth, Structure, and Electronic Properties
- 2011
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 11:12, s. 5401-5407
-
Tidskriftsartikel (refereegranskat)abstract
- A novel strategy for efficient growth of nitrogen-doped graphene (N-graphene) on a large scale from s-triazine molecules is presented. The growth process has been unveiled in situ using time-dependent photoemission. It has been established that a postannealing of N-graphene after gold intercalation causes a conversion of the N environment from pyridinic to graphitic, allowing to obtain more than 8096 of all embedded nitrogen in graphitic form, which is essential for the electron doping in graphene. A band gap, a doping level of 300 meV, and a charge-carrier concentration of similar to 8 x 10(12) electrons per cm 2, induced by 0.4 atom % of graphitic nitrogen, have been detected by angle-resolved photoeinission spectroscopy, which offers great promise for implementation of this system in next generation electronic devices.
|
|
| 2. |
- Usachov, D., et al.
(författare)
-
Quasifreestanding single-layer hexagonal boron nitride as a substrate for graphene synthesis
- 2010
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 82:7
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that freeing a single-atom thick layer of hexagonal boron nitride (h-BN) from tight chemical bonding to a Ni(111) thin film grown on a W(110) substrate can be achieved by intercalation of Au atoms into the interface. This process has been systematically investigated using angle-resolved photoemission spectroscopy, x-ray photoemission, and absorption techniques. It has been demonstrated that the transition of the h-BN layer from the "rigid" into the "quasifreestanding" state is accompanied by a change in its lattice constant. Using chemical vapor deposition, graphene has been successfully synthesized on the insulating, quasifreestanding h-BN monolayer. We anticipate that the in situ synthesized weakly interacting graphene/h-BN double layered system could be further developed for technological applications and may provide perspectives for further inquiry into the unusual electronic properties of graphene.
|
|
| 3. |
- Haberer, D., et al.
(författare)
-
Anisotropic Eliashberg function and electron-phonon coupling in doped graphene
- 2013
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 88:8
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate, with high-resolution angle-resolved photoemission spectroscopy, the spectral function of potassium-doped quasi-free-standing graphene on Au. Angle-dependent x-ray photoemission and density functional theory calculations demonstrate that potassium intercalates into the graphene/Au interface, leading to an upshift of the K-derived electronic band above the Fermi level. This empty band is what makes this system perfectly suited to disentangle the contributions to electron-phonon coupling coming from the pi band and K-derived bands. From a self-energy analysis we find an anisotropic electron-phonon coupling strength lambda of 0.1 (0.2) for the K Gamma (K M) high-symmetry directions in momentum space, respectively. Interestingly, the high-energy part of the Eliashberg function which relates to graphene's optical phonons is equal in both directions but only in K M does an additional low-energy part appear.
|
|
| 4. |
|
|
| 5. |
- Mascher, Martin, et al.
(författare)
-
A chromosome conformation capture ordered sequence of the barley genome
- 2017
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 544:7651, s. 427-433
-
Tidskriftsartikel (refereegranskat)abstract
- Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
|
|
