Sreetosh Goswami1 Santi Rath2 Svante Hedstrom3 Victor Batista3 Sreebrata Goswami2 Thirumalai Venkatesan1

1, National Univ of Singapore, Singapore, , Singapore
2, Indian Association for the Cultivation of Science, Kolkata, West Bengal, India
3, Yale University, New Haven, Connecticut, United States

In the next generation of digital technology, which includes forward-looking consumer electronics and the internet-of-things, non-volatile memory will play a decisive role where flash memory is currently the key player. However, as flash memory fails to meet the commercial demands of scalability and endurance, the industry is looking for an alternative where resistive memory devices are leading candidates. Organic resistive memories are of particular interest because of their low-cost solution-processability and synthetic tunability. However, to date, they have been lacking reproducibility, endurance, retention, switching speed, and the mechanistic understanding required for commercial translation. In this report, we demonstrate a resistive memory device with a spin-coated active layer of a transition metal complex where we have achieved unprecedented reproducibility (~350 devices), fast switching (<30 ns), excellent endurance (~1012 cycles), and retention (>106 s). We establish a definitive switching mechanism via in-situ Raman and UV-Vis-spectroscopy alongside spectroelectrochemistry and quantum chemical calculations and find that the redox state of the ligands determines the switching states of the device while the counterions control the hysteresis. Both in terms of device performance and understanding, this study presents a significant step forward in organic resistive memory technology [1,2].

[1] Goswami, Sreetosh, et al. "Robust resistive memory devices using solution-processable metal-coordinated azo aromatics." Nature Materials (2017), DOI: 10.1038/NMAT5009
[2] Valov, Ilia, and Michael Kozicki. "Non-volatile memories: Organic memristors come of age." Nature Materials (2017): nmat5014