Enhancement of field-effect mobility in molybdenum-disulfide transistor through the treatment of low-power oxygen plasma

Abstract

We experimentally demonstrate that the treatment with low-power oxygen plasma can raise the field-effect mobility in molybdenum-sulfide (MoS2) transistors from 0.01 to 9.6 cm2 V−1 s−1, which is an increment of about three orders of magnitude. The decrease in threshold voltage and the increase in the drain current of the devices indicate that the electron density increases significantly after the mild plasma treatment. The emergence of Mo–O characteristics but the suppression of Mo–S features on the X-ray photoelectron spectrum of the plasma-treated sample suggests that a portion of the MoS2 film becomes conductive molybdenum oxide. This transformation may considerably upgrade the performance of MoS2 transistors.