Biomemristor based on a natural medicinal plant (Tinospora cordifolia) and their phototunable resistive switching properties integrated with carbon quantum dots

Implementing biocompatible and biodegradable information storage would be a giant leap toward next-generation green electronics. Natural biomaterial-based memristors, with their proven prospective applications due to their sustainable, non-toxic, eco-friendly, degradable, and biocompatible characteristics, will not only save our environment from harmful chemicals and e-wastes while also allowing the electronic industry to grow. In this work, a biomaterials-inspired thin film was successfully created from the leaf extract of the traditional medicinal herb giloy (Tinospora cordifolia) for biomemristor applications. The electronic-grade giloy thin film spin coated on FTO/glass using aqueous giloy solution exhibits remarkable transparency over the majority of the visible spectral range. A reasonable bipolar reversible and non-volatile resistive switching behaviour was obtained. In addition, incorporating carbon quantum dots (CQDs) with giloy to generate a CQDs@giloy composite film resulted in phototunable resistive switching characteristics with a 16% decrease in SET voltage. A reasonable memristive behaviour such as proper endurance, retention and a steady resistance ratio between high and low resistance states over 100 consecutive switching cycles and 100 flexing cycles was obtained. The conduction mechanisms were analysed. Finally, a mechanism in combination with the formation/annihilation of an Ag metal filament and ionized molecular vacancy filament is proposed to explain the resistive switching behaviour.