Hot Carriers in CVD-Grown Graphene Device with a Top h-BN Layer

الملخص EN

We investigate the energy relaxation of hot carriers in a CVD-grown graphene device with a top h-BN layer by driving the devices into the nonequilibrium regime.

By using the magnetic field dependent conductance fluctuations of our graphene device as a self-thermometer, we can determine the effective carrier temperature T e at various driving currents I while keeping the lattice temperature T L fixed.

Interestingly, it is found that T e is proportional to I, indicating little electron-phonon scattering in our device.

Furthermore the average rate of energy loss per carrier P e is proportional to ( T e 2 - T L 2 ), suggesting the heat diffusion rather than acoustic phonon processes in our system.

The long energy relaxation times due to the weak electron-phonon coupling in CVD graphene capped with h-BN layer as well as in exfoliated multilayer graphene can find applications in hot carrier graphene-based devices.