Photoelectric memristor based on a PZT/NSTO heterojunction for neuromorphic computing applications

Abstract

Inspired by the human brain and visual system, neuromorphic computing based on a photoelectric memristor overcomes the limitations of the traditional von Neumann architecture and has attracted the interest of researchers. In this work, a high-quality epitaxial Pb(Zr_0.4Ti_0.6)O₃ (PZT) thin film was prepared through a sol–gel method as the functional layer of a photoelectric memristor, and a heterojunction with a conductive substrate Nb:SrTiO₃ (NSTO) was formed. The heterojunction device could not only successfully emulate the fundamental functions of the synapse, such as paired-pulse facilitation (PPF) and post-tetanic potentiation (PTP) under the condition of electrical regulation, but could also achieve the modulation of conductance under pulses with different UV light intensities by taking advantage of the persistent photoconductivity of the device. Moreover, with the characteristics of photoelectric co-modulation, a 7 × 7 photoelectric memristor array was prepared, which not only successfully simulates the classic Tetris game but also realizes the reconfigurable logic functions of “AND” and “OR”. This work proves that the PZT/NSTO heterojunction photoelectric memristor can show brain-like sensor characteristics and open up potential applications of photoelectric memristors in the next generation of brain-like neuromorphic computing.