Effects of carbonized spent coffee grounds in honey thin film on resistive switching

In the pursuit of more sustainable electronics, this study explores the incorporation of carbonized spent coffee grounds (SCGs) into honey-based resistive switching memory devices. SCGs, a by-product of coffee production, were thermally treated at 150, 350, 450, and 500°C to modify their carbon content and surface functional groups. The treated SCGs were incorporated into honey, a natural polysaccharide, to form a composite memristive layer. Thin films were prepared by spin-coating and drying, followed by fabrication of Au/carbonized SCGs-honey/indium–tin–oxide (ITO) devices using sputtered Au and ITO as the top and bottom electrodes, respectively. Thermogravimetric analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy indicated that increasing the treatment temperature increased carbon content, structural disorder, and carbonyl-group density while reducing hydroxyl-group content. Current–voltage measurements showed that the ON/OFF ratio increased from approximately ∼101.35 to ∼102.27 corresponding to an approximately eightfold increase. The memory window decreased by 0.34 V, from 2.30 to 1.96 V, for devices containing SCGs treated at 500°C compared with those containing undried SCGs. These findings demonstrate that thermally treated SCGs can enhance the resistive switching performance of honey-based thin films.