Electronic band gaps and exciton binding energies in monolayer MoxW1-xS2 transition metal dichalcogenide alloys probed by scanning tunneling and optical spectroscopy

Article

关键词: 2-DIMENSIONAL MATERIALS;    SINGLE;    MOS2;    PHOTOLUMINESCENCE;    WS2;    STATES;    PROGRESS;    GROWTH;    SPIN;   

DOI  :  10.1103/PhysRevB.94.075440

来源: SCIE

【 摘 要 】

Using scanning tunneling spectroscopy (STS) and optical reflectance contrast measurements, we examine band-gap properties of single layers of transition metal dichalcogenide (TMDC) alloys: MoS2, Mo0.5W0.5S2, Mo0.25W0.75S2, Mo0.1W0.9S2, and WS2. The quasiparticle band gap, spin-orbit separation of the excitonic transitions at the K/K' point in the Brillouin zone, and binding energies of the A exciton are extracted from STS and optical data. The exciton binding energies change roughly linearly with tungsten concentration. For our samples on an insulating substrate, we report quasiparticle band gaps from 2.17 +/- 0.04 eV(MoS2) to 2.38 +/- 0.06 eV(WS2), with A exciton binding energies ranging from 310 to 420 meV.

【 授权许可】

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