2014/03/31 by A. V. Kretinin, Y. Cao, J. S. Tu +18 · 4 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Boron nitride #Graphene #Graphene foam #Graphene oxide paper #Graphene research and applications #Hexagonal boron nitride #Oxide #Pentoxide #Substrate (aquarium) #Transition Metal Oxide Nanomaterials #Tungsten #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1021/nl5006542
published as Nano Letters 14, 3270 - 3276 (2014) · 19 pages, 11 figures, 1 table including Supporting Information
openalex publication_date 2014/05/20 · arxiv created 2014/05/24 · arxiv updated 2014/07/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Hexagonal boron nitride is the only substrate that has so far allowed graphene devices exhibiting micrometer-scale ballistic transport. Can other atomically flat crystals be used as substrates for making quality graphene heterostructures? Here we report on our search for alternative substrates. The devices fabricated by encapsulating graphene with molybdenum or tungsten disulfides and hBN are found to exhibit consistently high carrier mobilities of about 60 000 cm(2) V(-1) s(-1). In contrast, encapsulation with atomically flat layered oxides such as mica, bismuth strontium calcium copper oxide, and vanadium pentoxide results in exceptionally low quality of graphene devices with mobilities of ∼1000 cm(2) V(-1) s(-1). We attribute the difference mainly to self-cleansing that takes place at interfaces between graphene, hBN, and transition metal dichalcogenides. Surface contamination assembles into large pockets allowing the rest of the interface to become atomically clean. The cleansing process does not occur for graphene on atomically flat oxide substrates.