Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2

• DOI: 10.1021/acs.nanolett.5b01967
• Publication Date: 2015-08-19T08:11:43Z
• Authors: Antonija Grubišić...; Jill A. Miwa; Signe S. Grønborg; Jonathon M. Riley; Jens C. Johannsen; Cephise Cacho; Oliver Alexander; Richard T. Chapman; Emma Springate; Marco Grioni; Jeppe V. Lauritsen; Phil D. C. King; Philip Hofmann; Søren Ulstrup
• Keywords: Free electron model; Free carrier

The dynamics of excited electrons and holes in single layer (SL) MoS$_2$ have so far been difficult to disentangle from the excitons that dominate optical response this material. Here, we use time- angle-resolved photoemission spectroscopy for a SL on metallic substrate directly measure free carriers. This allows us ascertain direct quasiparticle band gap 1.95 eV determine an ultrafast (50 fs) extraction carriers via metal contact with MoS$_2$. process is key importance optoelectronic applications rely separated rather than excitons.