Influence of electrolyte selection on performance of tantalum anodic oxide memristors

Anodic memristors obtained by electrochemical anodization of Ta in phosphate, borate and citrate buffer so-lutions are studied. Memristive behaviour is demonstrated by electrical switching between high and low conductive states. The endurance and retention of devices are analysed. The use of phosphate leads to 4 switching levels and the highest ratio between high and low resistive states. All studied oxides are stoichiometric Ta2O5 and only P is detected inside anodic memristors. The improved memristive characteristics of oxides anodized in phosphate are attributed to an increase of O vacancies due to the presence of Ta oxyphosphate, which is believed to mediate spatial pinning of conductive filaments positions during read/write. The anodic memristors show high stability, enhanced endurance and retention that combined with their active layer low fabrication cost makes them ideal candidates for industrial implementation.