Grain Boundary Enabled Diamond Memristor

Diamond has been recognized as the ultimate semiconductor due to its ultra-wide bandgap, exceptional carrier mobility, high breakdown voltage, and superior thermal conductivity. However, its application in memristors is significantly limited by challenges in modulating its electrical conductivity and its chemical stability. Here, by leveraging the rapid metal-diamond reactions at diamond grain boundaries (GBs), we constructed vertical ion migration channels along the GBs and realized the nonvolatile resistive switching behavior in polycrystalline diamond (Poly-D). The diamond memristor presents a high switching ratio (∼10⁴) along with reliable cycling and retention performance over a wide temperature range from -150°C to 600°C. In-situ biasing transmission electron microscopy observations confirm the reproducible formation and rupture of Ag conductive filaments (Ag CFs) along the constructed channels at the GBs. The diamond memristor demonstrates its capabilities as an artificial synapse and in biological nociception. Our work demonstrates the application of diamond in memristors and highlights its potential for neuromorphic computing, particularly under extreme conditions.