Copper (II) Phthalocyanine (CuPc) Based Optoelectronic Memory Device with Multilevel Resistive Switching for Neuromorphic Application

The 1D nanotubular organic semiconductor, copper (II) phthalocyanine (CuPc), embedded in poly-methyl methacrylate (PMMA) is employed for the first time for multilevel resistive switching (RS) and neuromorphic applications. Single-double bonded planar CuPc tubes are synthesized via simple solvothermal methods and dispersed in the PMMA solution with different weight concentrations. The composite sample is deposited on an ITO coated transparent, flexible and conducting PET substrate to form Ag/CuPc@PMMA/ ITO device. I-V characterizations of the cell reveal a formation free, bipolar, non-volatile, multilevel RS effect. The device shows a significantly large resistance ON/OFF ratio of 10(4), low threshold operating voltage (<2 V), large endurance (>10(4) cycles) and long retention time (>10(4) s) at room temperature. The multilevel resistive states are induced by visible light illumination. Based on the experimental data, the conduction mechanism of this type of RS memory device under the optical and the electrical impulse is attributed by the charge trapping and detrapping methods. The synaptic short-term and long-term potentiation are also studied on the device during the identical pulse training process. The proposed RS active material is a potential candidate for future artificial neural systems that simulate characteristics of human memory.

Automated summary

In this study, a one-dimensional nanotubular organic semiconductor, copper (II) phthalocyanine (CuPc), embedded in poly-methyl methacrylate (PMMA) was utilized for multilevel resistive switching (RS) and neuromorphic applications. The device demonstrated a large resistance ON/OFF ratio, low threshold operating voltage, large endurance, and long retention time. The conduction mechanism under optical and electrical impulse was attributed to charge trapping and detrapping methods, showing potential for future artificial neural systems.