Light-induced enhancement of memory effect in self-assembled pyrene nanostructures

A one-pot self-assembly method for the growth of one-dimensional nanoribbons of pyrene with high yield is reported. Nitric acid-treated pyrene molecules are self-assembled to form nanoribbons at room temperature. Morphological structure, composition, crystallinity and functionality of nitric acid-treated pyrene have been studied by electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. A significant modification in optical absorption and properties is observed in pyrene nanoribbons as compared to pristine pyrene. Electrical resistive switching in dark and under illumination is observed in single pyrene nanoribbons down to 100 nm width and length determined by deposited nanoelectrodes of spacing similar to 500 nm, for the first time. Almost a four-order enhancement in ON/OFF switching current ratio is observed under illumination compared to that of dark, paving the way for small molecular nanoassembly-based light-controlled memory devices in future.