A Low-Voltage Solution-Processed Organic Small Molecule Memristor Based on TIPS Pentacene

Organic small molecule-based memristors offer the advantage of low-cost, large-area fabrication. Despite this advantage, the uncertainty in electrical switching mechanisms and device reproducibility coupled with stability issues in different operating environments impede further development of these organic memory devices. Moreover, the potential barrier height at the interface between the electrode and the organic active material is crucial in controlling charge dynamics. In this report, an environmentally stable, solution-processed, small molecule 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS Pentacene)-based memristor has been fabricated with two different top electrodes Au and Ag. Ag as a top electrode device has shown characteristics of bipolar nonvolatile memory with a low set voltage of around 0.5 V. Besides lower operating voltage, the device exhibits high retention (>10⁴ s) and a good ON/OFF ratio. In contrast, devices with Au electrodes showed no resistive switching behavior. The switching mechanism is also investigated, and it is found to be governed by charge trapping/detrapping in conjunction with the trap-controlled space-charge-limited-conduction model. The finding is also supported by capacitance measurements on the memory device. These results indicate the strong potential of solution-processed TIPS Pentacene memristors for non-volatile memory applications and pave the way for lower power consumption data storage in organic electronics.