Static and Dynamic Performance of Complementary Inverters Based on Nanosheet α-MoTe2 p -Channel and MoS2 n-Channel Transistors

Molybdenum ditelluride (alpha-MoTe2) 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 alpha-MoTe2 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 alpha-MoTe2 as the semiconductor for the p-channel FETs and MoS2 as the semiconductor for the n-channel FETs. To avoid ambipolar behavior and produce alpha-MoTe2 FETs with dean p-channel characteristics, we have employed the high-workfunction metal platinum for the source and drain contacts. As a result, our alpha-MoTe2 nanosheet p-channel FETs show hole mobilities up to 20 cm(2)/(V s), on/off ratios up to 105, and a subthreshold slope of 255 mV/decade. For our complementary inverters composed of few-layer alpha-MoTe2 p-channel FETs and MoS2 n-channel FETs we have obtained voltage gains as high as 33, noise margins as high as 0.38 V-DD, a switching delay of 25 mu s, and a static power consumption of a few nanowatts.