W-Shaped Antiambipolar Transistors Based on h-BN/MoTe₂/BP Heterostructures

The development of multifunctional device architectures capable of integrating logic, analog, and optoelectronic functions is critical for overcoming the scaling and energy efficiency limitations of conventional CMOS technologies. Antiambipolar transistors (AATs), with their nonmonotonic transfer characteristics and central Λ-shaped region, provide an attractive platform for implementing multivalued logic operations, compact frequency multipliers, and photodetectors. Here, we present a high-performance W-shaped AAT based on an h-BN/MoTe₂/BP van der Waals heterostructure. The device exhibits four discrete conductance states and a symmetric Λ-region centered at V_gs = 0 V, with a high on/off current ratio exceeding 10⁵ and peak currents in the microampere range. These properties enable the implementation of a ternary inverter with uniformly spaced 20 V logic windows and excellent operational stability over 200 switching cycles. In addition, the symmetric Λ-region facilitates bias-free frequency doubling, providing a low-power solution for analog signal processing. Furthermore, the device functions as a gate-tunable photovoltaic photodetector with dynamically reversible photocurrent polarity. It achieves a rectification ratio ranging from 10^-3 to 10³, a dark current below 0.5 pA, a photoresponsivity of 0.29 A/W, an external quantum efficiency (EQE) of 69.4%, and a fast response time of 100 μs. These results position W-shaped AATs as a potential platform for next-generation nanoelectronic and optoelectronic systems requiring reconfigurability, energy efficiency, and high integration density.