Charge-mediated remote epitaxy of Ga 2 O 3 via MoS 2

Remote epitaxy of the corundum phase α-Ga 2 O 3 is demonstrated through a domain-free, transfer-free monolayer of MoS 2 template synthesized on sapphire. Despite the intrinsic nonidealities of MoS 2 —specifically its thickness and polar bonding characteristics—for remote epitaxy, single-crystalline α-Ga 2 O 3 films are epitaxially grown on polycrystalline MoS 2 with crystallographic fidelity comparable to those grown directly on bare sapphire. This observation substantiates that the substrate lattice potential can still be effectively transmitted through the MoS 2 layer, facilitating epitaxial registry at the growth front. The resulting α-Ga 2 O 3 films exhibit crystal quality and surface morphology on par with those grown directly on bare sapphire. Moreover, a centimeter-scale, crack-free α-Ga 2 O 3 membrane was successfully exfoliated using a Ni stressor, underscoring the mechanical compatibility and scalability of the remote epitaxial process. Structural disordering observed with more-than-bilayer MoS 2 further corroborates the remote epitaxy mechanism. First-principles calculations reveal that interfacial interactions between the bottom S atoms of MoS 2 and the Al atoms of sapphire induce spatially modulated charge distributions on the MoS 2 surface, creating energetically favorable adsorption sites for Ga species. Collectively, these findings establish a mechanistic framework for charge-mediated remote epitaxy across polar interfaces and expand the design space for heterogeneous integration of transferable wide bandgap Ga 2 O 3 membranes in next-generation power electronics and optoelectronic devices.