Observation of large positive magneto-resistance in bubble decorated graphene oxide films derived from shellac biopolymer: a new carbon source and facile method for morphology-controlled properties†

We report a large positive magneto-resistance (MR) in bubble decorated graphene oxide films that are
derived from shellac biopolymer as a carbon source. These films were produced on a quartz substrate by
heating the biopolymer coated substrate at 900 °C in an argon atmosphere. The characterization data of
the films using Raman, X-ray photoelectron spectroscopy, field emission scanning electron microscopy
and transmission electron microscopy reveal that shellac can be used as a new carbon source to produce
transparent bubble decorated graphene oxide films. The magneto-resistance results show a 130% change
in the resistance of the films at 3 K under a perpendicular magnetic field of 15 T, and the value decreases
exponentially up to 50 K. The observed MR properties of the bubble decorated graphene oxide films are
explained using a weak anti-localization and quantum interference model in the low magnetic field
region, while the Lorentz force accounts for the MR properties well in the high magnetic field region.