2014/06/19 by Chun Hung Lui, C. H. Lui, A. J. Frenzel +13
Chemistry · Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Analytical Chemistry (journal) #Atomic physics #Chemistry #Condensed matter physics #Doping #Exciton #Graphene research and applications #Materials science #Optoelectronics #Perovskite Materials and Applications #Photoconductivity #Physics #Semiconductor #Trion #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.113.166801
published as Phys. Rev. Lett. 113, 166801 (2014)
arxiv created 2014/06/19 · openalex publication_date 2014/10/16 · arxiv updated 2014/10/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Optical excitation typically enhances electrical conduction and low-frequency radiation absorption in semiconductors. We, however, observe a pronounced transient decrease of conductivity in doped monolayer molybdenum disulfide (MoS(2)), a two-dimensional (2D) semiconductor, using ultrafast optical-pump terahertz-probe spectroscopy. In particular, the conductivity is reduced to only 30% of its equilibrium value at high pump fluence. This anomalous phenomenon arises from the strong many-body interactions in the 2D system, where photoexcited electron-hole pairs join the doping-induced charges to form trions, bound states of two electrons and one hole. The resultant increase of the carrier effective mass substantially diminishes the conductivity.