▎ 摘　　要

In atmospheric-pressure chemical vapor deposition-grown multilayer graphene films, a reversible change from n- to p-type conductivity has been observed in the temperature range of 25A degrees C to 150A degrees C upon exposure to hydrogen. This study was conducted with a simple Pd/graphene/Pd planar device. The inversion was observed at around 100A degrees C, below which it showed stable n-type response to hydrogen. The hydrogen response was quite fast (1 s to 2 s) at 150A degrees C. A plausible mechanism has been developed to explain such inversion. The selectivity and stability of the device in both n- and p-regions were investigated in the temperature range of 25A degrees C to 150A degrees C.