Rath Santi P, Thompson Damien, Goswami Sreebrata, Goswami Sreetosh
Centre for Nanoscience and Engineering, CeNSE, Indian Institute of Science (IISc), Bangalore, Karnataka, 560012, India.
Department of Physics, University of Limerick, Limerick, V94 T9PX, Ireland.
Adv Mater. 2023 Sep;35(37):e2204551. doi: 10.1002/adma.202204551. Epub 2022 Sep 28.
Electronic transitions in molecular-circuit elements hinge on complex interactions between molecules and ions, offering a multidimensional parameter space to embed, access, and optimize material functionalities for target-specific applications. This opportunity is not cultivated in molecular memristors because their low-temperature charge transport, which is a route to decipher molecular many-body interactions, is unexplored. To address this, robust, temperature-resilient molecular memristors based on a Ru complex of an azo aromatic ligand are designed, and current-voltage sweep measurements from room temperature down to 2 K with different cooling protocols are performed. By freezing out or activating different components of supramolecular dynamics, the local Coulombic interactions between the molecules and counterions that affect the electronic transport can be controlled. Operating conditions are designed where functionalities spanning bipolar, unipolar, nonvolatile, and volatile memristors with sharp as well as gradual analog transitions are captured within a single device. A mathematical design space evolves, thereof comprising 36 tuneable parameters in which all possible steady-state functional variations in a memristor characteristic can be attainable. This enables a deterministic design route to engineer neuromorphic devices with unprecedented control over the transformation characteristics governing their functional flexibility and tunability.
分子电路元件中的电子跃迁取决于分子与离子之间的复杂相互作用，为针对特定目标应用嵌入、获取和优化材料功能提供了一个多维参数空间。分子忆阻器尚未利用这一契机，因为其低温电荷传输这一用于解读分子多体相互作用的途径尚未得到探索。为解决这一问题，设计了基于偶氮芳香配体的钌配合物的坚固且耐温的分子忆阻器，并采用不同的冷却方案进行了从室温到2 K的电流-电压扫描测量。通过冻结或激活超分子动力学的不同组分，可以控制影响电子传输的分子与抗衡离子之间的局部库仑相互作用。设计了这样的工作条件，即在单个器件中能够实现涵盖具有尖锐及渐变模拟转变的双极、单极、非易失性和易失性忆阻器的功能。由此演化出一个数学设计空间，其中包含36个可调节参数，在这些参数下忆阻器特性中所有可能的稳态功能变化均可实现。这使得能够通过确定性设计路线来制造神经形态器件，以前所未有的方式控制决定其功能灵活性和可调性的转变特性。
