Low-temperature photocarrier dynamics in monolayer MoS2

T. Korn; S. Heydrich; M. Hirmer; J. Schmutzler; C. Schüller

doi:10.1063/1.3636402

paper

Low-temperature photocarrier dynamics in monolayer MoS2

arXiv:1106.2951 · doi:10.1063/1.3636402

Abstract

The band structure of MoS $_{2}$ strongly depends on the number of layers, and a transition from indirect to direct-gap semiconductor has been observed recently for a single layer of MoS $_{2}$ . Single-layer MoS $_{2}$ therefore becomes an efficient emitter of photoluminescence even at room temperature. Here, we report on scanning Raman and on temperature-dependent, as well as time-resolved photoluminescence measurements on single-layer MoS $_{2}$ flakes prepared by exfoliation. We observe the emergence of two distinct photoluminescence peaks at low temperatures. The photocarrier recombination at low temperatures occurs on the few-picosecond timescale, but with increasing temperatures, a biexponential photoluminescence decay with a longer-lived component is observed.

3 pages, 4 figures