Web-drive based source measure unit for automated evaluations of ionic liquid-gated MoS₂ transistors

For reliable characterization of two-dimensional semiconducting devices and continuous monitoring in toxic environments, construction of an electrical characterization-based massive database using a portable source measure unit (SMU) with a WiFi connection is desirable. The web-drive based SMU using a microcontroller developed here exhibits superior voltage source performance (∼1 mV) and voltage/current measurement (∼0.15 mV/∼1 nA) capabilities, with automatic construction of a measurement database for online storage using web-drive based software, which can be applied for reliable electrical characterization. Electrical characterization of ionic liquid-gated MoS₂ transistors was achieved with the designed SMU and showed results comparable with those obtained using a commercial semiconductor characterization system. Ionic liquid-gated transistors only require a small gate bias (∼1.5 V) for on-state operation because of the high gate capacitance originating from the thin dielectric layer constructed of an electrical double layer, which makes the device a promising candidate for low power consumption applications. Finally, several electrical parameters of the ionic liquid-gated transistor were extracted from the datasets and uploaded to the web-drive.