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

Abstract

Abstract 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 (Δ V g ) 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 MoTe 2 /MoS 2 . Flexible modulation of carrier concentration and transport by gate voltage achieves a driving voltage range Δ V g as high as 38.4 V and a PVR of 1.6 × 10 2 . Most importantly, MoTe 2 /MoS 2 exhibits a pronounced gate-tunable photoresponse, which is attributed to the modulation of photogenerated carrier transport by gate voltage. The MoTe 2 /MoS 2 heterojunction photodetector exhibits excellent performance, including an impressive responsivity of 17 A W −1 , a high detectivity of 4.2 × 10 11 cm Hz 1/2 W −1 , an elevated external quantum efficiency of 4 × 10 3 %, and a fast response time of 21 ms. Gate-tunable photodetectors based on MoTe 2 /MoS 2 heterostructures AAT have potential to realize optoelectronic devices with high performance, providing a novel strategy to achieve high-performance photodetection.