Selective atomic layer deposition onto directly transferred monolayer graphene

Abstract

We demonstrated the direct transfer of graphene using a modified mechano-electro-thermal method, which induces no defects, leaves no residue and does not fold the surface. We executed the atomic layer deposition (ALD) of Al2O3 using an H2O-based precursor and compared the results of selective deposition onto direct-transfer graphene with the results of deposition onto graphene by a conventional wet transfer. After ALD, the intensity ratios of D-G peaks from the Raman spectra and the height profiles of wet-transferred graphene increased from 0.104 to 1.416 and from 0.980 nm to 1.804 nm, respectively. In addition, the electrical sheet resistance and water contact angle of wet-transferred graphene changed from 1.534 k Omega/rectangle and 85.8 degrees to 2.247 k Omega/rectangle and 66.9 degrees, respectively. However, direct-transfer graphene exhibit similar values even after ALD. These results indicate that Al2O3 was deposited onto the active ALD nucleation sites of wet-transferred graphene, whereas direct-transfer graphene exhibited selective ALD growth.