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

• Published in: IEEE photonics technology letters Vol. 32; no. 6; pp. 329 - 332
• Main Authors: Dixit, Tejendra, Tripathi, Akash, Ganapathi, K. L., Rao, M. S. Ramachandra, Singh, Vipul
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.03.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomedical optical imaging; CuO thin films; Excitation; Gold; Gold coatings; Holographic optical components; Holography; Low temperature; Memory devices; NIR excitation; Optical crosstalk; Optical films; optical memory; Optical memory (data storage); persistent photoconductivity; Photoconductivity; Thin films
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2020.2973725

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 (<inline-formula> <tex-math notation="LaTeX">\lambda _{\mathrm {ex}}=254 </tex-math></inline-formula> nm) was used while for the RESET, NIR (<inline-formula> <tex-math notation="LaTeX">\lambda _{\mathrm {ex}}=800 </tex-math></inline-formula> 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.