Capacitive coupling between an overlying ion gel electrolyte and an underlying oxide thin film is utilized to substantially suppress the operating voltage of field-effect transistors (FETs) based on two-dimensional (2D) transition metal dichalcogenides and black phosphorus. The coupling of the layers is achieved following device fabrication by laminating an ion gel layer over an oxide-gated 2D FET through solution-casting methods. While the original pristine 2D FET requires tens of volts for gating through the oxide layer, the laminated ion gel layer reduces the operating voltage to below 4 V even when the same underlying substrate is used as the back gate electrode. Moreover, this capacitive coupling approach allows low-voltage operation without compromising the off-current level, which often occurs when ion gel electrolytes are directly employed as the gate dielectric material. This approach can likely be generalized to a wide variety of thin-film FETs as a postfabrication method for reducing operating voltages and power consumption.
Bibliographical noteFunding Information:
J. H. Cho acknowledges financial support from the Center for Advanced Soft Electronics (CASE) under the Global Frontier Research Program, Korea (NRF-2013M3A6A5073177). M. C. Hersam and T. J. Marks acknowledge financial support from the Materials Research Science and Engineering Center (MRSEC) of Northwestern University (NSF DMR-1121262). This work made use of the Northwestern University Atomic and Nanoscale Characterization Experimental Center (NUANCE), which has received support from the NSF MRSEC (DMR-1121262), State of Illinois, and Northwestern University. In addition, the Raman instrumentation was funded by the Argonne-Northwestern Solar Energy Research (ANSER) Energy Frontier Research Center (DOE DE-SC0001059).
© 2017 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry