Large-Area Black\nPhosphorus by Chemical Vapor Transport\nfor Vertical and Lateral Memristor Devices

Black\nphosphorus (BP) has emerged as a promising 2D material for\nnext-generation electronic and optoelectronic devices in the past\ndecade. Recently, the chemical vapor transport (CVT) method has been\na widely adopted technique for synthesizing high-quality BP films.\nIn this work, we report the successful growth of large-area BP films\nusing CVT method, achieving epitaxial growth on Au<sub>3</sub>SnP<sub>7</sub>/SiO<sub>2</sub>/Si substrates. The resulting BP films were\nsystematically characterized by atomic force microscopy (AFM), Raman\nspectroscopy, X-ray diffraction (XRD), scanning electron microscopy\n(SEM), and transmission electron microscopy (TEM). These characterizations\nconfirmed the high quality, crystallinity, and uniformity of the BP\nfilms. We further integrated the BP films into both vertical and lateral\nmemristor structures. The vertical BP memristor structure demonstrated\na 2 × 2 crossbar array with excellent endurance over 30000 cycles\nand an ON/OFF ratio exceeding 25. Meanwhile, the lateral BP memristor\nexhibited long-term plasticity (LTP) and long-term depression (LTD)\ncharacteristics, requiring a pulse width as short as 10 μs,\nmaking these devices promising candidates for neuromorphic computing\napplications.