Passivating Graphene and Suppressing Interfacial Phonon Scattering with Mechanically Transferred Large-Area Ga<sub>2</sub>O<sub>3</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36410928.
- Also identified by DOI 10.1021/acs.nanolett.2c03492 and PMC identifier 9837877.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We demonstrate a large-area passivation layer for graphene by mechanical transfer of ultrathin amorphous Ga<sub>2</sub>O<sub>3</sub> synthesized on liquid Ga metal. A comparison of temperature-dependent electrical measurements of millimeter-scale passivated and bare graphene on SiO<sub>2</sub>/Si indicates that the passivated graphene maintains its high field effect mobility desirable for applications. Surprisingly, the temperature-dependent resistivity is reduced in passivated graphene over a range of temperatures below 220 K, due to the interplay of screening of the surface optical phonon modes of the SiO<sub>2</sub> by high-dielectric-constant Ga<sub>2</sub>O<sub>3</sub> and the relatively high characteristic phonon frequencies of Ga<sub>2</sub>O<sub>3</sub>. Raman spectroscopy and electrical measurements indicate that Ga<sub>2</sub>O<sub>3</sub> passivation also protects graphene from further processing such as plasma-enhanced atomic layer deposition of Al<sub>2</sub>O<sub>3</sub>.