Self-Assembly Of An Organic Radical Thin Film And Its Memory Function Investigated Using A Liquid-Metal Electrode

In this work, the deposition of a persistent organic radical by thermal evaporation on Au, Pt, and graphene is performed. The impact of the deposition parameters and the nature of the substrate on the molecular organization within the deposited film are investigated. The nonplanarity of the molecule and the role of the molecule-molecule and molecule-substrate interactions are discussed. UV photoelectron spectroscopy experiments demonstrate that the radical character, and hence its magnetic and redox properties, is preserved on the three surfaces. The optimized films are electrically characterized by top-contacting the film/substrate system using a liquid metal that permits achievement of a soft contact avoiding damaging the layer. The hysteretic current versus voltage curves obtained from the electrical characterization point to the potential applicability of the studied system as an organic memory. Moreover, the demonstrated feasibility of using a liquid metal is an appealing approach toward the preparation of flexible devices.