Low Temperature CVD Grown Graphene for Highly Selective Gas Sensors Working under Ambient Conditions

In this paper we report on gas sensors based on graphene grown by Chemical Vapor Deposition at 850 °C. Mo was used as catalyst for graphene nucleation. Resistors were directly designed on pre-patterned Mo using the transfer-free process we recently developed, thus avoiding films damage during the transfer to the target substrate. Devices operating at room temperature and relative humidity set at 50% were tested towards NO2. The sensors resulted to be highly specific towards NO2 and showed current variation up to 6%. The performances were compared with those of gas sensors based on graphene grown at 980 °C, which represents the usual growth temperature for such material. The findings show that by lowering the graphene growth temperature and consequently the energy consumptions the sensing benefits of these devices are still preserved.