Resistive switching characteristics and conduction mechanisms of nonvolatile memory devices based on Ga and Sn co-doped ZnO films

• Nonvolatile memory devices were fabricated utilizing Ga and Sn co-doped ZnO (GZTO) films.
• X-ray diffraction patterns showed that the annealed GZTO films were an amorphous phase.
• Current–voltage measurements on the devices showed bipolar resistive switching behaviors.
• One order magnitude difference in resistance between low and high resistance states (HRS)
• Space charge limited conduction is the dominant conduction mechanisms of the HRS.

Nonvolatile memory devices were fabricated utilizing Ga and Sn co-doped ZnO (GZTO) films formed by using a solution process method. X-ray diffraction patterns showed that the crystallinity of the annealed GZTO films was an amorphous phase. X-ray photoelectron spectroscopy spectra of the GZTO films depicted ZnO, GaO, and SnO bonds. Current–voltage measurements on the Al/GZTO/indium-tin-oxide (ITO) devices at 300 K showed bipolar resistive switching behaviors. The resistances at both the low resistance state (LRS) and high resistance state (HRS) measured at 0.5 V for the devices maintain almost constant without any damage and breakdown above 130 s, indicative of the memory stability of the devices. A difference in the resistance between the HRS and the LRS was more than 1 order of the magnitude. The conduction mechanisms of the HRS in the set process for the Al/GZTO/ITO devices were dominated by a space-charge-limited current model.