Tantalum pentoxide (Ta2O5 and Ta2O5-x)-based memristor for photonic in-memory computing application

Photonic in-memory computing exhibits promising potential to address the inherent limitations of traditional von Neumann architecture. In this study, we demonstrate a tantalum pentoxide (Ta2O5 and Ta2O5−x)-based memristor as a non-volatile memory for photonic in-memory computing functions. The active layer of the memristor on a heavily doped N-Si substrate comprises two films of Ta2O5 and Ta2O5−x with a size of 3 × 3 µm2 of which roughness root-mean-square values are 1.25 nm and 1.59 nm, respectively. A controllable electrical behavior transition from write-once-read-many-times (WORM) memory to resistive random-access memory (RRAM) is achieved by changing the depositional sequence. Benefitting from the visible light response, the in situ photonic Boolean logic operations (“AND/OR”) are achieved in the RRAM device by mixing the light and electric signals, and the power consumption of an “AND” or “OR” operation consumes 4.503 nJ and 4.526 nJ, respectively, proving the superior photonic in-memory computing potential. The basic logic “IMPLICATION” operation is implemented by performing electrical regulation in a circuit with two RRAM devices connected in parallel. Finally, a 5 × 5 RRAM array is developed and thereafter, the array-level logic for image processing applications is realized. The proposed tantalum pentoxide-based memristors possess great potential in constructing efficient in-memory computing architectures.