Large-Area Black Phosphorus by Chemical Vapor Transport for Vertical and Lateral Memristor Devices

Black phosphorus (BP) has emerged as a promising 2D material for next-generation electronic and optoelectronic devices in the past decade. Recently, the chemical vapor transport (CVT) method has been a widely adopted technique for synthesizing high-quality BP films. In this work, we report the successful growth of large-area BP films using CVT method, achieving epitaxial growth on Au3SnP7/SiO2/Si substrates. The resulting BP films were systematically characterized by atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). These characterizations confirmed the high quality, crystallinity, and uniformity of the BP films. We further integrated the BP films into both vertical and lateral memristor structures. The vertical BP memristor structure demonstrated a 2 × 2 crossbar array with excellent endurance over 30000 cycles and an ON/OFF ratio exceeding 25. Meanwhile, the lateral BP memristor exhibited long-term plasticity (LTP) and long-term depression (LTD) characteristics, requiring a pulse width as short as 10 μs, making these devices promising candidates for neuromorphic computing applications.