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.