Access to hole dynamics in graphite by femtosecond luminescence and photoemission spectroscopy

Ultrafast dynamics of holes in a solid is usually hard to observe directly because the optical transition includes both electron and hole dynamics. In this paper we show an approach combining femtosecond luminescence and photoemission spectroscopy, successfully applied to graphite. Ultrafast infrared luminescence is observed in graphite and ascribed to recombination luminescence, though graphite is a semimetal. The dynamics of holes is deduced by taking a ratio between the time-resolved luminescence and photoemission data recorded on the same sample, and shown to be very close to that of electrons.