Abstract
Two dimensional (2D) molecular crystals have attracted considerable attention because of their promising potential in electrical device applications, such as high-performance field-effect transistors (FETs). However, such devices demand high voltages, thereby considerably increasing power consumption. This study demonstrates the fabrication of organic FETs based on 2D crystalline films as semiconducting channels. The application of high-κ oxide dielectrics allows the transistors run under a low operating voltage (−4 V). The devices exhibited a high electrical performance with a carrier mobility up to 9.8 cm2 V−1 s−1. Further results show that the AlOx layer is beneficial to the charge transport at the conducting channels of FETs. Thus, the device strategy presented in this work is favorable for 2D molecular crystal-based transistors that can operate under low voltages.
Highlights
Given that the capacitance and gate leakage current are both critical to the gate dielectric in low-voltage OFETs, we employ an Au/AlOx/ Si capacitor structure
The thermally deposited AlOx can be used as a gate insulating layer because of its superior performance as a dielectric material
The previous results show that C8-BTBT molecules in first layer are more tilted to the substrate than that in upper layers, because the weak van der Waals interactions among the small molecules decrease rapidly from the dielectric surface to the upper molecular layers[6, 26]
Summary
The bilayer crystalline films and AlOx are used as conducting channels and gate dielectrics, respectively, to fabricate the planar transistors. The device exhibits a high electrical performance and yields a carrier mobility of up to 6.5 cm[2] V−1 s−1, near-zero threshold voltage of −0.7 V, small subthreshold swing of 160 mV dec−1, and large on/off ratio of >105. To the best of our knowledge, our device exhibits a record-high value of the carrier mobility for low-voltage OFETs (Supplementary Table S2).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
