%0 Journal Article
%T Temperature induced inversion of oxygen response in CVD graphene on SiO2
%A Raivo Jaaniso
%A Tauno Kahro
%A Jekaterina Kozlova
%A Jaan Aarik
%A Lauri Aarik
%A Harry Alles
%A Aare Floren
%A Alar Gerst
%A Aarne Kasikov
%A Ahti Niilisk
%A V£żino Sammelselg
%J Physics
%D 2013
%I arXiv
%R 10.1016/j.snb.2013.09.068
%X We have synthesized single-layer graphene on Cu foils using chemical vapor deposition method and transferred the graphene to the top of a Si/SiO2 substrate with a pair of prefabricated Ti/Au electrodes. A resistive graphene-based gas sensor prepared in this way revealed n-type oxygen response at room temperature and we have successfully fitted the data obtained with varying oxygen levels using a two-site Langmuir model. P-type oxygen response of our sensor was observed after the temperature was raised to 100 oC, with a reversible transition to n-type behaviour when the temperature was lowered back to room temperature. Such inversion of the gas response type with temperature was interpreted as a result of interplay between the adsorbate-induced charge transfer and charge carrier scattering. The transduction function was derived, which relates the electrical response to surface coverage through both the induced mobility and charge density changes.
%U http://arxiv.org/abs/1310.0215v1