Anomalous electrical bistability in lateral grain rich polycrystalline molybdenum disulfide thin films

Lateral-grain- rich polycrystalline MoS2 films have been prepared using sulfurization of the Mo-coated glass substrate. The goal of such synthesis is to achieve electrical bistability without fabricating a sandwiched structure that generally utilizes other materials, such as graphene or N-vinylcarbazole. These films show a symmetrical three-stage electrical behavior that follows a different charge transport mechanism. In a single voltage sweep, both on and off stages appear. The intermediate stage obeys a trap-controlled space charge limited current mechanism, whereas the ON stage follows a Schottky emission model. The overall charge transport mechanism was explained on the basis of contributions from dangling bonds, stoichiometric defects, atmospheric adsorbates, s-vacancies, and free charge carriers. Under an assumption of the high contribution of the leakage current, the simulated I-V curve shows two different sections. Such a trend was observed in the experimental I-V curves.