Van der Waals ferroelectric semiconductor tunnel junction with ultra‐low switching voltage

Ferroelectric tunnel junctions (FTJs) hold great promise for neuromorphic computing due to their advantages of low energy consumption, high speed, and nonvolatile multi‐level resistance states. However, achieving a programming voltage below 1 V in FTJs, a critical requirement for neuromorphic computing, is hindered by the high energy barrier of traditional ferroelectric materials. Here, we report an all‐two‐dimensional (2D) FTJ based on the van der Waals (vdW) ferroelectric semiconductor AgBiP 2 Se 6 . Benefiting from the low polarization‐switching barrier of AgBiP 2 Se 6 and the high‐quality interface of the all‐2D structure, the vdW ferroelectric semiconductor tunnel junction (FSTJ) demonstrates robust memory characteristics. Reproducible DC resistive switching over 600 cycles at an operating voltage below 0.2 V can be achieved in the FSTJ, coupled with outstanding memory performance including long data retention (>10 4 s) and a fast write speed of 100 ns. Beyond basic memory functions, the device also serves as a promising platform for neuromorphic computing. Potentiation and depression (LTP/LTD) synaptic behaviors with high linearity (0.68 for LTP, 0.23 for LTD) and symmetricity (94.7) can be emulated at a minimum programming voltage of 0.05 V, enabling successful system‐level image recognition simulations. These results highlight the potential of vdW FSTJs for low‐power memory and neuromorphic computing applications. image