Reversible charge-polarity control for a photo-triggered anti-ambipolar In ₂ Se ₃ &WSe ₂ heterotransistor

Based on the charge-polarity control, a novel anti-ambipolar heterotransistor is proposed based on a special In₂Se₃&WSe₂ van der Waals heterostructure. Unlike traditional logic transistors, our anti-ambipolar heterotransistor can treat an optical signal as an input to change its operating state, that is, with the switching of the optical signal, it shows a reversible polarity change between anti-ambipolar and P-type. Moreover, with the increase of laser power density from 0 to 4.4 mW cm^-2, the current value corresponding to the anti-ambipolar peak of the device (I_peak) shifts from 0 to 4.3 nA, and the voltage value corresponding to the anti-ambipolar peak of the device (V_peak) can shift from -7 to -5.67 V. These phenomena demonstrate that the charge neutrality point of the anti-ambipolar heterotransistor can be selectively varied with the change of laser power density. In addition, the aforementioned device possesses a high I_on/I_off ratio of about 10⁴ (405 nm, 4.4 mW cm^-2) at 0 V. These properties indicate that our unique anti-ambipolar In₂Se₃&WSe₂ heterotransistor can be employed in photo-triggered inverters for future optoelectronic circuits, and it has great potential to improve the integration of overall chip circuits by implementing optoelectronic logic functions in a unit.