Type: Latvian Council of Science Projects

Agreement No: lzp-2020/1-0345

Duration: 01.01.2021 – 31.12.2023.

Project Leader: Dr.hab.phys. Juris Purans

Project partners: Institute of Solid State Physics University of Latvia (ISSP UL).

Total budget: 281 478 EUR

ISSP UL budget:  281 478 EUR

Project description:

Motivated by the high demand for transparent electrical conductors, in this fundamental project we will investigate the topological-like electrical conductivity in Ga2O3 thin films grown via MOCVD on different orientation (including off-axis) sapphire substrates that could be applied in Ga2O3 -based transparent electrodes in ultraviolet optoelectronic devices. The key result will be deeper physical understanding of sapphire substrate crystallographic orientation impact on topological-like metallic conductivity in β– Ga2O3 thin films. Information about epitaxial relations between the film and the substrate together with advanced in-depth film characterization methods might elucidate the surface conductivity mechanism. The origin of a such exceptionally robust conduction merits to be investigated more deeply, because it challenges our current understanding and ways to achieve solar-transparent conducting electrodes in a wide bandgap insulator.

The planned activities include establishment of the MOCVD process for growing epitaxial monocrystalline β–Ga2O3 thin films, investigation of as-grown thin film electrical properties together with detailed structural, compositional and optical characterization of the films by traditional laboratory and advanced synchrotron radiation methods with focus on surface properties and possible donor doping, and large-scale theoretical calculations to elucidate the possible surface conductivity mechanisms.