Non-destructive photovoltaic reading of interface type memristors using graphene as transparent electrode

The memristor device based on graphene/Nb-doped SrTiO3 heterojunction was fabricated. The device exhibits obvious resistive switching between high resistance state and low resistance state. By using the graphene as the transparent electrode, remarkable photocurrent and photovoltage was achieved in the heterojunction. The photovoltage shows a clear dependence on the resistance state, whereas the photocurrent keeps unchanged. Based on these features, a new non-destructive photovoltaic reading method of the memristor was demonstrated. The photovoltaic reading method is free of external driving voltage, thereby avoiding the perturbation of the stored data. Moreover, the photovoltage output signal instead of the current is more compatible with the IC technologies.