Metal-Organic Framework Nanofilm for Mechanically Flexible Information Storage Applications

Metal-organic frameworks (MOFs), which are formed by association of metal cations or clusters of cations (nodes) with soft organic bridging ligands (linkers), are a fascinating class of flexible crystalline hybrid materials offering potential strategy for the construction of flexible electronics. In this study, a high-quality MOF nanofilm, HKUST-1, on flexible gold-coated polyethylene terephthalate substrates is fabricated using liquid phase epitaxy approach. Uniform and reproducible resistive switching effect, which can be sustained under the strain of as high as 2.8%, and over the wide temperature range of -70 to + 70 degrees C, is observed for the first time in the all solid-state Au/HKUST-1/Au/thin film structures. Through conductive atomic force microscopic and depth-profiling X-ray photoelectron spectroscopicanalysis, it is proposed that the electric field-induced migration of the Cu2+ ions, which may lead to subsequent pyrolysis of the trimesic acid linkers and thus the formation of highly conducting filaments, could be the possible origin for the observed uniform resistance switching in HKUST-1 nanofilms.