Band-like transport behavior of H-doped transition metal dichalcogenide (TMD) channels in field effect transistors (FET) is studied by conducting low-temperature electrical measurements, where MoTe2, WSe2, and MoS2 are chosen for channels. Doped with H atoms through atomic layer deposition, those channels show strong n-type conduction and their mobility increases without losing on-state current as the measurement temperature decreases. In contrast, the mobility of unintentionally (naturally) doped TMD FETs always drops at low temperatures whether they are p- or n-type. Density functional theory calculations show that H-doped MoTe2, WSe2, and MoS2 have Fermi levels above conduction band edge. It is thus concluded that the charge transport behavior in H-doped TMD channels is metallic showing band-like transport rather than thermal hopping. These results indicate that H-doped TMD FETs are practically useful even at low-temperature ranges.
Bibliographical noteFunding Information:
The authors acknowledge the financial support from NRF (NRL program: Grant No. 2017R1A2A1A05001278, SRC program: Grant No. 2017R1A5A1014862, vdWMRC center). S.O. and H.J.C. acknowledge the financial support from the NRF (Grant No. 2011-0018306). Computational resources were provided by the KISTI Supercomputing Center (Project No. KSC-2018-CRE-0097).
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All Science Journal Classification (ASJC) codes
- Materials Science(all)