Direct exciton emission from atomically thin transition metal dichalcogenide heterostructures near the lifetime limit.

ABSTRACT: We demonstrate the reduction of the inhomogeneous linewidth of the free excitons in atomically thin transition metal dichalcogenides (TMDCs) MoSe₂, WSe₂ and MoS₂ by encapsulation within few nanometre thick hBN. Encapsulation is shown to result in a significant reduction of the 10 K excitonic linewidths down to ∼3.5 meV for n-MoSe₂, ∼5.0  meV for p-WSe₂ and ∼4.8 meV for n-MoS₂. Evidence is obtained that the hBN environment effectively lowers the Fermi level since the relative spectral weight shifts towards the neutral exciton emission in n-doped TMDCs and towards charged exciton emission in p-doped TMDCs. Moreover, we find that fully encapsulated MoS₂ shows resolvable exciton and trion emission even after high powe

SUBMITTER: Wierzbowski J 

PROVIDER: S-EPMC5620059 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature