On August 27, 2026, Šarūnas Jankauskas, a doctoral student at the Institute of Materials Science, defended his doctoral dissertation “Direct synthesis of horizontal graphene by microwave plasma enhanced chemical vapor deposition and its application in electronic devices” in the field of materials engineering.
The dissertation investigates the direct synthesis of horizontal graphene films on dielectric and semiconductor substrates (Si, SiO2, Al2O3, h-BN) using microwave plasma-enhanced chemical vapor deposition (MW-PECVD), bypassing complex transfer processes. Structural characterization revealed nanostructured multi-layer graphene with a typical flake height of 1.0 – 1.3 nm and dominant grain-boundary defects.
The study established optimized parameters—including methane-to-hydrogen ratios, stable 10 mBar chamber pressure, and a protective steel shield to minimize plasma-induced damage—enabling low-temperature synthesis below 600 °C and hydrogenated graphene formation at 400 °C. Practical device applications were successfully demonstrated: introducing an h-BN dielectric interlayer enhanced photocurrent and open-circuit voltage in graphene/”Si” photodiodes, while directly synthesized graphene field-effect transistors (G-FET) exhibited exceptional biosensing sensitivity, achieving a ultra-low SARS-CoV-2 spike protein detection limit of 10E-2 fg/mL.
