Novel phase-transformed gallium oxide thermal interface nanomaterials engineered by ion beams

Project goal: to perform a fundamental study of nano-to-microscale thermal transport in phase-transformed gallium oxide interface thermal nanostructures engineered by high-precision ion-beam engineering to reach predictive understanding of thermal transport performance in future power electronics and thermoelectric systems.

Project description: The need for new interface thermal nanomaterials based on ultrawide bandgap semiconductors is in high demand in advanced power electronics as well as in thermoelectrics. Spatially selective ion implantation is proposed to manipulate thermal transport in Ga2O3 crystals via novel ion-induced transformation from β- to γ-crystalline phase. Radiation-induced phase-transformed Ga2O3 structures as well as nano-patterned periodic superlattices with regularly shaped interfaces will be fabricated to tailor thermal interfaces across γ- and β-phases. Heat propagation in these novel thermal nanomaterials will be investigated by advanced laser-based thermoreflectance techniques with nano- to micro-meter depth resolution in conjunction with multi-scale heat conduction modeling

Project facilitators: Azat Abdullayev (Leading researcher), Kairolla Sekerbayev (Senior researcher), Lyazzat Mukhangaliyeva (Junior Researcher), Rustem Tlegenov (Junior Researcher).

Realisation period: 2023-2025

Expected results: The obtained results of the project are planned to be published in leading international peer-reviewed journals of editorial offices such as Elsevier, AIP Publishing, APS Physics etc.
- at least 2 (two) articles and (or) reviews in peer-reviewed scientific publications in the scientific direction of the project, indexed in the Science Citation Index Expanded of the Web of Science database and (or) having a CiteScore percentile in the Scopus database of at least 35 (thirty-five);
- or at least 1 (one) article or review in a peer-reviewed scientific publication in the scientific direction of the project, indexed in the Science Citation Index Expanded of the Web of Science database and (or) having a CiteScore percentile in the Scopus database of at least 35 (thirty-five), and at least 1 (one) patent included in the database Derwent Innovations Index data (Web of Science, Clarivate Analytics);
- at least 1 (one) article or review in a peer-reviewed foreign or domestic publication recommended by the CQAES;
- or at least 1 (one) article or review in a peer-reviewed scientific publication indexed in the Science Citation Index Expanded and included in the 1st (first) quartile by impact factor in the Web of Science database;

Methodology: In this project, we will fabricate γ-phase Ga2O3 films and nano-structures by irradiating β-phase Ga2O3 wafers with ion beams having energies over keV – MeV range. Moreover, we will test the fabrication of periodic heterostructures (superlattices) consisting of γ- and β- phases to manipulate heat conduction. Importantly, by applying several irradiation regimes such as atomic, cluster, and sequential ion implantation, we intend to investigate the role of the γ/β interface quality on interface thermal conductance. The irradiation recipes will be constantly tailored by thermal propagation measurement and structural characterization techniques such as XRD, RBS-C and TEM. The core part of the work is in the advanced laser-based thermoreflectance measurements of thermal transport in the fabricated structures. We will non-destructively probe the depth-resolved thermal transport data on micro- to nanometer scale using time-domain thermoreflectance (TDTR) and modulated thermoreflectance (MTR) setups. Measured results will be used to validate multiscale modeling ranging from molecular dynamics to semi-analytical Klemens-Callaway continuum model of phonon-mediated heat transport in irradiated Ga2O3 structures.

Contacts: Azat Abdullayev, azat.abdullaev@nu.edu.kz, +77472723929