Temperature- and Hydrogen-Gas-Dependent Reversible Inversion of n-/ p-Type Conductivity in CVD-Grown Multilayer Graphene (MLG) Film.

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 25°C to 150°C upon exposure to hydrogen. This study was conducted with a simple Pd/graphene/Pd planar device. The inversion was observed at around 100°C, below which it showed stable n-type response to hydrogen. The hydrogen response was quite fast (1 s to 2 s) at 150°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 25°C to 150°C. [ABSTRACT FROM AUTHOR]