Electronic properties of CVD graphene: The role of grain boundaries, atmospheric doping, and encapsulation by ALD

Grain boundaries and unintentional doping can have profound effects on graphene‐based devices. Here we study these in detail for CVD grown poly‐crystalline monolayer graphene with two significantly different grain size distributions centered around 10–25 μm and 100–400 μm. Although the two types of...

Full description

Saved in:
Bibliographic Details
Published in:Physica Status Solidi. B: Basic Solid State Physics 2016-12, Vol.253 (12), p.2321-2325
Main Authors: Van Veldhoven, Zenas A., Alexander-Webber, Jack A., Sagade, Abhay A., Braeuninger-Weimer, Philipp, Hofmann, Stephan
Format: Article
Language:English
Subjects:
ALD
Atomic layer deposition
CVD
Devices
Doping
Encapsulation
field effect transistors
Grain boundaries
Grains
Graphene
mobility
Transport properties
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Grain boundaries and unintentional doping can have profound effects on graphene‐based devices. Here we study these in detail for CVD grown poly‐crystalline monolayer graphene with two significantly different grain size distributions centered around 10–25 μm and 100–400 μm. Although the two types of graphene are processed under identical conditions after growth, they show distinct transport properties in field effect transistor devices. While all as‐fabricated samples showed similar p‐type doping, the smaller grain size type graphene with larger number of grain boundaries exhibit lower average mobility. In order to separate out the effects of grain boundaries and doping from ambient exposure on the transport properties, the devices were encapsulated with Al2O3 by atomic layer deposition. The encapsulation of large grain samples thereby showed drastic improvements in the performance with negligible doping while the small grain samples are largely intolerant to this process. We discuss the implications of our data for the integrated manufacturing of graphene‐based device platforms.
ISSN:0370-1972
1521-3951
DOI:10.1002/pssb.201600255