Multilayer Black\nPhosphorus/Hexagonal Boron Nitride/Graphene\nHeterostructure Metal–Insulator–Semiconductor Diode

Assembling two-dimensional (2D) crystals via weak van\nder Waals\n(vdW) interactions in a vertical stack reveals various exciting physical\nphenomena and becomes essential for high-performance electronic devices\nthrough band alignment modulation. These vdW heterostructures enable\nthe creation of primary electronic components, such as diodes and\ntransistors, facilitating multifunctional device integration on a\nsingle chip and offering significant potential for analog and digital\nelectronics. This study demonstrates the potential of metal–insulator–semiconductor\n(MIS) diodes within 2D vdW heterostructures, focusing on a combination\nof black phosphorus (BP), thin hexagonal boron nitride (hBN), and\ngraphene (Gr). The BP/hBN/Gr MIS diode is fabricated using a dry transfer\nmethod to vertically stack the layered materials. Comparative analysis\nwith similar metal–semiconductor diodes reveals superior current\nrectification in the MIS diode, attributed to carrier tunneling at\nthe interfaces. We evaluate the performance metrics, including the\nrectification ratio, ideality factor, and tunneling behavior, over\na temperature range of 77–300 K. The device exhibits a rectification\nratio of 3.5 × 10<sup>2</sup> and an ideality factor of 1.6.\nOur findings highlight the potential of MIS diodes in ultrathin nanoelectronics,\noffering insights for future advancements in electronic and optoelectronic\ndevices.