Sensitivity investigation for the dependence of monolayer and stacking graphene NH3 gas sensor

The influence of various stacking chemical vapor deposition (CVD) graphene on ammonia sensing is investigated. Three interdigitated electrodes (IDEs) gas sensor with non-stacking monolayer (NSM), less stacking double layer (LSDL) and more stacking few layer (MSFL) CVD graphene were fabricated for ammonia gas detection. NSM sensor is more sensitive than LSDL and MSFL ones towards NH3. Especially for 12,500 ppm NH3, the sensitivity of NSM device is more than twice the LSDL device and almost 7 times of MSFL device. Moreover, the repeatability and response time of NSM device are all much better than the other two. The simulation results show that the change ratios of integral electrons in total DOS changed 26.65% after NH3 adsorption for monolayer graphene, which is three times more than triple layer graphene of 8.29%. This is the reason why NSM has the highest sensitivity towards NH3. (C) 2016 Elsevier B.V. All rights reserved.