Reactive intercalation and oxidation at the buried graphene-germanium interface

Abstract

We explore a number of different electrochemical, wet chemical, and gas phase approaches to study intercalation and oxidation at the buried graphene-Ge interface. While the previous literature focused on the passivation of the Ge surface by chemical vapor deposited graphene, we show that particularly via electrochemical intercalation in a 0.25 N solution of anhydrous sodium acetate in glacial acetic acid, this passivation can be overcome to grow GeO2 under graphene. Angle resolved photoemission spectroscopy, Raman spectroscopy, He ion microscopy, and time-of-flight secondary ion mass spectrometry show that the monolayer graphene remains undamaged and its intrinsic strain is released by the interface oxidation. Graphene acts as a protection layer for the as-grown Ge oxide, and we discuss how these insights can be utilized for new processing approaches.

Epitaxial graphene/Ge interfaces: a minireview

“…The electrochemical oxidation of the gr/Ge(110) interface was performed in Ref. 92 with the goal to stabilise a grapheneprotected GeO 2 . It was possible to prepare 350 nm-thick GeO 2 layer at the gr/Ge(110) interface via electrochemical intercalation in a 0.25 N solution of anhydrous sodium acetate in glacial acetic acid.…”

Process Pathway Controlled Evolution of Phase and Van‐der‐Waals Epitaxy in In/In2O3 on Graphene Heterostructures

“…Beyond 2D materials our work also has a potential implication in the wider context of controlled In-oxide growth: [48][49][50][51][52] Graphene can be grown via CVD on a variety of device relevant materials. [81,82] Therefore, our finding that graphene can impose controlled vdW epitaxy to an In 2 O 3 overlayer also suggests that exploration of graphene as a templating buffer-layer may be promising toward the controlled growth of In 2 O 3 on non-In 2 O 3lattice-matched device-relevant materials.…”

Materials Science Challenges to Graphene Nanoribbon Electronics

“…The latter could enable the direct fabrication of top-gated GNR devices on Ge(001). The formation of stable, uniform films of Ge oxide underneath GNRs via thermal oxidation or electrochemical intercalation could be explored . Alternatively, for GNRs synthesized on Ge-on-Si(001), alignment-preserved transfer to Si(001) via chemical vapor etching of the Ge epilayer or via wafer-bonding could be investigated (Figure ).…”