Molecular vibrational mid-IR radiation amplified by high-biased graphene

Mid-infrared (mid-IR) emission resonating with molecular vibration is one of the important pathways to deliver heat energy required for various chemical reactions. However, its practical applications have been limited due to the lack of high-power large-area mid-IR sources so far. Here we report that graphene layers coupled with the vibrational excitation modes of substrates can generate intense mid-IR radiation at high bias. This is potentially related to the high-current driven nonequilibrium phenomena, where sonic-boom-like shock waves at the graphene/substrate interface can induce the overflow of excited molecular vibrations in substrates followed by spontaneous or stimulated transitions to ground states. The resulting mid-IR radiation is highly efficient in thermal energy generation and transfer, which is expected to significantly reduce power consumption in homes and industries.