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We present a study of the electrical, structural and chemical properties of Ti contacts on atomic layer deposited α-Ga2O3 film. Ti forms an ohmic contact with α-Ga2O3. The contact performance is highly dependent on the post-evaporation annealing temperature, where an improved conductivity is obtained when annealing at 450 °C, and a strong degradation when annealing at higher temperatures. Structural and chemical characterisation by transmission electron microscopy techniques reveal that the electrical improvement or degradation of the contact upon annealing can be attributed to oxidation of the Ti metallic layer by the Ga2O3 film in combination with the possibility for Ti diffusion into the Au layer. The results highlight that the grain boundaries and inclusions in the Ga2O3 film provide fast diffusion pathways for this reaction, leaving the α-Ga2O3 crystallites relatively unaffected—this result differs from previous reports conducted on β-Ga2O3. This study underlines the necessity for a phase-specific and growth method-specific study of contacts on Ga2O3 devices.

High-performance graphene nanopapers are prepared from an aqueous solution of functional graphenes with benzenesulfonic acid groups via covalent bonds. The formed hydrophobic graphene nanopapers showed the highest tensile strength of 360 MPa and Young's modulus of 102 GPa for samples with 13.7 wt % functional group and annealed at 150 °C. These samples showed a high electrical conductivity of 4.45 × 10(4) S/m after being annealed at 250 °C. The aforementioned properties of graphene nanopapers are much higher than any previously reported data. The properties of nanopapers depend on the degree of functionality on graphenes and the annealing temperatures, which are further evidenced by X-ray photoelectron spectroscopy, FTIR, and X-ray diffraction patterns. Such unique nanopapers can be easily bounded and sandwiched onto any solid surface to give rise to great potentials in many applications such as gas diffusion barriers, EMI shielding, thermal management, and anticorrosion.