Our main research interest is to systematically understand and control the energy flow between photons, electrons, and phonons in carbon based nanomaterials for developing new energy harvesting technologies at single molecular level. We will address the key scientific challenges by (1) designing and fabricating carbon-based nanoscale devices with in-situ tunable electronic properties; (2) investigating energy flow dynamics and mechanisms by spatial, photon energy and time resolved scanning photocurrent microscopy and optical spectroscopy; (3) integrating carbon-based nanostructures with other advanced photonic systems such as plasmonics and silicon waveguides for new device functionalities. Our research will impact and lead to new nanoscale optoelectronics, ranging from light emitting diodes and transparent electrodes, to ultrafast photodetectors and solar cells.