16:00 〜 18:00
▲ [18p-P10-1] Comparison of excited state dynamics between graphene and graphite by using transient absorption spectroscopy
キーワード：graphene, Carrier dynamics
The ultrafast optical response of reduced graphene oxide (RGO) and graphite powder is investigated in this study, aiming future application of optical switching. We used ultrafast visible-pump/IR-probe femtosecond transient absorption spectroscopy in diffuse reflectance geometry to measure charge transfer kinetics. Picosecond decay is obtained due to intra-band relaxation. The subsequent rise was observed in RGO, while graphite shows stable response with time. The long lifetime component for RGO may be obtained because of charge transfer to the remaining grapheme oxide. Therefore, large gap is observed between RGO and graphene spectra. Inter-band contribution is also observed in both the samples as small negative dip at the time zero.