Charge Transport and Carrier Polarity Tuning by Electrolyte Gating in Nickel Benzenehexathiol Coordination Nanosheets

Abstract

AbstractCoordination nanosheets (CONASHs) or conjugated metal organic frameworks (MOFs) with distinctive metal‐organic bonding structures exhibit promise for electronics, sensing, and energy storage. Porous Nickel‐Benzene hexathiol complex (Ni‐BHT) with noteworthy conductivity was first reported a decade ago, and recent synthetic modifications produced non‐porous Ni‐BHT with enhanced conductivity (≈50 S cm−1). Here the charge transport physics of such non‐porous Ni‐BHT films are studied with even higher conductivity (≈112 S cm−1). In contrast to the thermally activated electrical conductivity, thermoelectric measurements suggest an intrinsic metallic nature of Ni‐BHT. It is shown that it is possible to tune the Fermi level and carrier polarity in Ni‐BHT by electrolyte gating; gating is initially governed by the formation of an interfacial, electric double layer and then evolves into an electrochemical (de)doping process. These findings not only contribute to a deeper understanding of charge transport in CONASHs, but also show that Fermi level tuning is an effective approach for enhancing the thermoelectric performance of CONASHs.