High-temperature memristors enabled by interfacial engineering

Nonvolatile memories (NVMs) that operate reliably at high temperatures are essential for electronics in extreme environments. Here, we report graphene (Gra)/HfO_x/tungsten (W) memristors that operated reliably up to 700°C, with an ON/OFF current ratio of >10³, data retention >50 hours, and endurance >10⁹ switching cycles. Transmission electron microscopy revealed substantial W diffusion into the inert platinum (Pt) electrode in conventional Pt/HfO_x/W memristors after high-temperature annealing, which was responsible for the thermal failure in conventional devices but not observed in Gra/HfO_x/W devices. First-principles calculations attributed the enhanced thermal stability to weaker W adsorption and higher surface diffusion barriers on Gra compared with metals such as Pt. These results underscore the critical role of interfacial engineering and the potential of two-dimensional materials for enabling reliable high-temperature NVM technologies.