Abstract

Integrating nanoporous metal-organic frameworks, MOFs, in electrical devices enables various applications, for instance, as sensor or memristor. The incorporation of thin MOF films in metal-insulator-semiconductor, MIS, capacitor structures is particularly attractive, since its operation at low voltages enables real-life applications. Here, thin Cu₃(BTC)₂, also referred to as HKUST-1, MOF films were deposited on thermally grown silicon dioxide surfaces in a layer-by-layer fashion. A peak of the conductance is observed, an evidence for interface states. Temperature dependent measurements reveal the formation of a counter clockwise hysteresis, due to charge injection mechanism. Finally, capacitance and conductance in strong accumulation decrease as the sample is heated slowly up to 100 °C. The cooling process results in a reverse process. Capacitance-voltage and conductance-voltage characteristics, measured in forward and reverse direction at different applied frequencies and temperatures, show the high quality of the interfaces which makes them suitable for advanced sensing and electronic applications. Capacitance and conductance curves of the p-Si/SiO₂/Cu₃(BTC)₂/Al MIS capacitor device showing the characteristically regimes of accumulation, depletion and inversion typical for a functional capacitor.

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