文摘
Molybdenum ditelluride (α-MoTe<sub>2sub>) is an emerging transition-metal dichalcogenide (TMD) semiconductor that has been attracting attention due to its favorable optical and electronic properties. Field-effect transistors (FETs) based on few-layer α-MoTe<sub>2sub> nanosheets have previously shown ambipolar behavior with strong p-type and weak n-type conduction. We have employed a direct imprinting technique following mechanical nanosheet exfoliation to fabricate high-performance complementary inverters using α-MoTe<sub>2sub> as the semiconductor for the p-channel FETs and MoS<sub>2sub> as the semiconductor for the n-channel FETs. To avoid ambipolar behavior and produce α-MoTe<sub>2sub> FETs with clean p-channel characteristics, we have employed the high-workfunction metal platinum for the source and drain contacts. As a result, our α-MoTe<sub>2sub> nanosheet p-channel FETs show hole mobilities up to 20 cm<sup>2sup>/(V s), on/off ratios up to 10<sup>5sup>, and a subthreshold slope of 255 mV/decade. For our complementary inverters composed of few-layer α-MoTe<sub>2sub> p-channel FETs and MoS<sub>2sub> n-channel FETs we have obtained voltage gains as high as 33, noise margins as high as 0.38 V<sub>DDsub>, a switching delay of 25 μs, and a static power consumption of a few nanowatts.