Effect of temperature–bias annealing on the hysteresis and subthreshold behavior of multilayer MoS2 transistors

The transfer characteristics (ID-VG) of multilayers MoS2 transistors with a SiO2/Si backgate and Ni source/drain contacts have been measured on as-prepared devices and after annealing at different temperatures (T-ann from 150 degrees C to 200 degrees C) under a positive bias ramp (V-G from 0 V to + 20 V). Larger T-ann resulted in a reduced hysteresis of the ID-VG curves (from similar to 11 V in the as-prepared sample to similar to 2.5 V after Tann at 200 degrees C). The field effect mobility (similar to 30 cm(2) V-1 s(-1)) remained almost unchanged after the annealing. On the contrary, the subthreshold characteristics changed from the common n-type behaviour in the as-prepared device to the…