Gate-tunable photodetectors based on MoTe2/MoS2 heterostructures anti-ambipolar transistors

Anti-ambipolar transistors (AATs) are considered as a breakthrough technology in the field of electronics and optoelectronics, which is not only widely used in diverse logic circuits, but also crucial for the realization of high-performance photodetectors. The anti-ambipolar characteristics arising from the gate-tunable energy band structure can produce high-performance photodetection at different gate voltages. As a result, this places higher demands on the parametric driving range (Delta Vg) and peak-to-valley ratio (PVR) of the AAT. Here, we demonstrate a high-performance photodetector with anti-ambipolar properties based on a van der Waals heterojunction of MoTe2/MoS2. Flexible modulation of carrier concentration and transport by gate voltage achieves a driving voltage range Delta Vg as high as 38.4 V and a PVR of 1.6 x 102. Most importantly, MoTe2/MoS2 exhibits a pronounced gate-tunable photoresponse, which is attributed to the modulation of photogenerated carrier transport by gate voltage. The MoTe2/MoS2 heterojunction photodetector exhibits excellent performance, including an impressive responsivity of 17 A W-1, a high detectivity of 4.2 x 1011 cm Hz1/2 W-1, an elevated external quantum efficiency of 4 x 103%, and a fast response time of 21 ms. Gate-tunable photodetectors based on MoTe2/MoS2 heterostructures AAT have potential to realize optoelectronic devices with high performance, providing a novel strategy to achieve high-performance photodetection.