Long-Lasting Persistent Photoconductivity in Au/CuO Thin Films for Optical Memory

Abstract

Persistent photoconductivity (PPC) in solution-processed pristine CuO and Au coated CuO thin films have been studied. Long-lasting PPC has been observed in Au coated CuO thin films with stable current levels even for 7 days. For the first time, long-lasting PPC effect in Au/CuO has been utilized for non-volatile optical memory. We have established both the SET and RESET processes using optical excitation. For the SET process, deep UV illumination ( $\lambda _{\mathrm {ex}}=254$ nm) was used while for the RESET, NIR ( $\lambda _{\mathrm {ex}}=800$ nm) excitation was used. In addition to the optical reset, low-temperature annealing (50 °C) was utilized for resetting the device. PPC effect in Au/CuO films has enormous possibility for next-generation commercial optical memory devices and neuromorphic computing.