Defect-engineered graphene-on-silicon-carbide platform for magnetic field sensing at greatly elevated temperatures

Properties of Z1 and Z2 Deep-Level Defects in n-Type Epitaxial and High-Purity Semi-Insulating 4H-SiC

“…The epitaxial layers were grown in an Epigress VP508 horizontal hot-wall chemical vapor deposition (CVD) reactor (Epigress, Lund, Sweden) using silane and propane as precursors. The layers with a thickness of ~10 µm were deposited in a flow of hydrogen, used as a carrier gas, at a temperature of 1600 • C. The epitaxial growth was performed on standard epi-ready n-type 4H-SiC wafers with a net donor concentration of ~2 × 10 18 cm −3 , oriented 4 • off of the (0001) plane toward the [11][12][13][14][15][16][17][18][19][20] direction. The substrates of 15 × 15 mm 2 in size were cut out from the wafers with a 4-inch diameter.…”

“…The properties of Z 1 and Z 2 defects were extracted from the temperature-induced changes in the photocurrent relaxation waveforms observed after switching off the UV pulse. The relaxation waveforms were analyzed under the assumption that the decay time of each waveform is much longer than the charge carrier's lifetime [12,13]. According to the assumed model, each relaxation waveform is described by the sum of the exponential components, whose the temperature-dependent time constants are equal to the reciprocals of the thermal emission rate of charge carriers for the defects contributing to the thermal emission process [12,13].…”

Origin of the Double Polarization Mechanism in Aluminum-Oxide-passivated Quasi-free-standing Epitaxial Graphene on 6H-SiC(0001)

“…25,26 The adsorption of hydroxyl groups is improved in n-doped graphene; 27,28 however, non-hydrogen-intercalated n-type graphene on SiC(0001) lacks the widely appreciated virtues of the p-type QFS one and is not the choice for applicationoriented research. 4 Literature suggests numerous methods for graphene prefunctionalization aimed to introduce additional bonds onto the graphene surface, for instance, the use of (a) a seed layer in the form of a thin layer of metal oxides, 29 metal nitrides 30 or organic compounds 31 and (b) reactive compounds, such as ozone 32 and fluorine. 33,34 However, seed layers may bring undesired impurities or breach chemical bonds in the graphene lattice, significantly degrading its charge carrier mobility.…”

“…As the EUROfusion consortium plans to replace its science-oriented International Thermonuclear Experimental Reactor (ITER) with an industry-driven demonstration fusion reactor (DEMO), so emerge future requirements for the plasma diagnostics and control systems . Among two-dimensional candidate materials for high-temperature magnetic field sensing under neutron radiation is graphene. − …”

“…The large TMA molecules attach to the surface of a material only until the methyl ligands block further access. , Another factor that affects the stoichiometry of ALD a-Al 2 O 3 is the limited number of reactive surface sites . This effect is particularly prominent in sp 2 -hybridized graphene. , The adsorption of hydroxyl groups is improved in n-doped graphene; , however, non-hydrogen-intercalated n-type graphene on SiC(0001) lacks the widely appreciated virtues of the p-type QFS one and is not the choice for application-oriented research …”