Grain Boundary Confinement of Silver Imidazole for Resistive Switching

Current resistive access memories (RRAM) suffer from severe resistive switching variability issues due to the large stochasticity in the formation and disruption process of conductive filaments. Here, a material strategy is applied in designing an RRAM device that can substantially improve the switching uniformity by utilizing a silver imidazole complex as the switching medium. In the silver imidazole, Ag species has a moderate reduction Gibbs energy which can participate in the redox reaction to change the resistance state of the device. Moreover, as a resistive layer, the migration range of silver ions is limited in the grain of silver imidazole, which shortens the migration distance of silver ions and reduces the randomness caused by silver ion migration, thus improving the uniformity and stability of the device. Through this facile material engineering strategy, the RRAM exhibits enhanced performance with low spatial variation of 7.86%, low temporal variation of 1.78% and low operation voltage of 0.50 V. The high switching uniformity of silver imidazole RRAM allows us to employ them as building blocks for logic gates with high yield. The self-reduction and grain boundary confinement effect of switching materials for RRAM design may open the way to the development of large-scale circuits for non-volatile computing and machine learning.