Multifunctional Phototransistor Based on MoS ₂ /Ta ₂ NiSe ₅ /WSe ₂ vdW Heterojunctions with High‐Performance Anti‐Ambipolar Transport

Abstract The anti‐ambipolar transistors based on van der Waals (vdW) heterojunctions, constructed from 2D materials, exhibit a variety of tunable physical properties, providing a versatile platform for the exploration of novel physical phenomena and the development of diverse electronic and optoelectronic device functions. Herein, this work presents MoS 2 /Ta 2 NiSe 5 /WSe 2 vdW heterojunctions with significant antiambipolar characteristics, achieving a peak‐to‐valley ratio as high as 2.04 × 10 3 , attributed to the synergistic effect of gate modulation on the MoS 2 /Ta 2 NiSe 5 and Ta 2 NiSe 5 /WSe 2 vdW heterojunctions. The MoS 2 /Ta 2 NiSe 5 /WSe 2 device implements a ternary inverter by the first Simulation Program with Integrated Circuit Emphasis model. The device also exhibits high‐performance photodetection under 532 nm illumination via the photogating effect, with performance metrics including responsivity ( R ) of 342.5 A W −1 and specific detectivity ( D * ) of 9.17 × 10 12 cm Hz 1/2 W −1 . Additionally, the heterojunction with two built‐in electric fields in the same direction via the photovoltaic effect can be used as self‐powered photodetectors, with a R of 392 mA W −1 and a D * of 5.1 × 10 12 cm Hz 1/2 W −1 . And MoS 2 /Ta 2 NiSe 5 /WSe 2 vdW photodetector is applied in the field of optical communication. This work not only achieves a multifunctional phototransistor with excellent electronic and optoelectronic performance but also demonstrates its significant potential in future “All‐in‐one” chip applications.