Achieving nearly barrier free transport in high mobility ReS2 phototransistors with van der Waals contacts
Shubhrasish Mukherjee, Gautam Samanta, Md. Nur Hasan, Shubhadip Moulick, Ruta Kulkarni, Kenji Watanabe, Takashi Taniguchi, A. Thamizhavel, Debjani Karmakar, Atindra Nath Pal
Abstract
Focusing on Rhenium disulfide (ReS 2 ), a group VII transition metal di-chalcogenides (TMDC), being a promising contender system for future nanoelectronics and optoelectronics, here, we present an innovative pathway to experimentally achieve an almost barrier-free contact for the ReS 2 field effect transistors (FETs) by using few layered graphene as contact electrodes, further supported by comparative first-principles analysis. Such barrier-free contacts enable the observation of metal-to-insulator transition with enhanced room temperature carrier mobility up to 25 cm 2 /Vs, linear I ds -V ds characteristic down to 80 K, along with the reduction of 1/f noise by more than two orders of magnitude. We further demonstrate a highly responsive gate- tunable phototransistor (R > 10 6 A/W) at an illumination wavelength of 633 nm. This work demonstrates a straightforward strategy to unlock the full potential of ReS 2 for CMOS compatible future electronic and optoelectronic devices.