Ultralow Contact Resistivity of Cu/Au With $p$ -Type ZnS Nanoribbons for Nanoelectronic Applications

Here, we report a new metallization scheme for achieving excellent ohmic contact to p-type II-VI nanostructures at room temperature. Bilayer electrodes consisting of Cu (4 nm)/Au (50 nm) provided a specific contact resistivity as low as 5.6 × 10^-7 Ω cm² with p-ZnS nanoribbons (NRs). Interface analysis via depth profiling X-ray photoemission spectroscopy, Auger electron spectroscopy, and high-resolution transmission electron microscopy revealed the formation of a highly conductive Cu₂S interfacial layer, which could serve as the buffer layer and thus promote the hole transport from NR to electrode. High-performance Ti/p-ZnS NR Schottky barrier diodes were then fabricated based on the Cu/Au ohmic contact.