Electrical transport properties of polycrystalline CVD graphene on SiO2/Si substrate

• DC conductivity and Hall mobility in the temperature range 2–460 K.
• Line defects are responsible for the deterioration of mobility and conductivity.
• Below 100 K, inter-grain transport is by quantum mechanical tunneling.
• At 100–290 K, the carriers transport themselves from GB traps to the neighboring grain.
• Above 290 K, mobility decreases with an increase of temperature, the effect of long range phonon.

Transport behavior of single layer graphene (SLG) grown by chemical vapor deposition technique on copper foil and transferred to SiO2/Si substrate has been studied by measuring the dc conductivity and Hall mobility in the temperature range 2–460 K. The samples of size 1 × 1 cm2 have been found to be polycrystalline in nature. Raman spectrum has been studied at various locations of the sample and the formation of SLG has been confirmed. From dc conductivity and mobility measurements it has been concluded that the one dimensional grain boundary defects are mainly responsible for the deterioration of mobility and conductivity of charge carriers in the polycrystalline samples.