摘要
We report Bi/MoS2/poly-Si memristors fabricated through a CMOS-compatible, transfer-free, and wafer-scale process. The semimetal Bi top electrode (TE) provides a low Schottky barrier and reduced contact resistance, enabling an ultrahigh on/off ratio exceeding 106 , endurance up to 103 cycles, and retention longer than 104 s. The devices show highly uniform bipolar switching with forming-free operation and tight cycle-to-cycle and device-to-device distributions. Time-dependent dielectric breakdown (TDDB) suggests improved resistance to constant-stress degradation in Bi-based devices compared with Al-capped counterparts, which is attributed to suppressed sulfur-vacancy-assisted leakage. Temperature-dependent I-V characteristics down to 20 K reveal distinct conduction regimes: direct tunneling and Poole-Frenkel emission in the high-resistance state (HRS), and a Schottky-to-Ohmic transition in the low-resistance state (LRS). The reduced trap density and contact barrier at the Bi/MoS2 interface account for the high switching ratio and stable low-temperature operation. These findings establish a quantitative correlation between electrode/interface engineering and charge-transport mechanisms, providing mechanistic insights into semimetal-2-D interfaces for low-power and reliable memory applications. © 1963-2012 IEEE.