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The integration of amorphous zinc tin oxide (ZTO) into crossbar memristor device structures has been investigated where asymmetric devices were fabricated with Al (top) and Pt (bottom) electrodes. The authors found that these devices had reproducible bipolar resistive switching with high switching ratios >104 and long retention times of >104 s. Electrical characterization of the devices suggests that both filamentary and interfacial mechanisms are important for device switching. The authors have used secondary ion mass spectrometry to characterize the devices and found that significant interfacial reactions occur at the Al/ZTO interface.

Bipolar switching is reported for the first time using solution deposited amorphous zinc-tin-oxide (ZTO). The impact of compliance current (CC) on the SET voltage, the magnitude of the low and high resistance states, and the switching ratio is investigated for Al/ZTO/Ir resistive random access memory (RRAM) devices.

The powder solution composite (PSC) method was used to obtain the conductivity of ZnO nanowires from impedance spectroscopy measurements of ZnO nanowires dispersed in solution. The PSC method was calibrated by comparing impedance spectroscopy measurements of ZnO powder dispersed in solution with four-point probe measurements on bulk ZnO ceramic pellets. Conductivity values for ZnO nanowires obtained using this novel approach were found to be comparable to reported values obtained using two-point and four-point probe measurements of single or multiple nanowire devices isolated on a substrate. It is shown that application of the PSC method to ZnO nanowire solutions avoids the difficult process of forming electrical contacts to nanowires and allows for the non-destructive in-situ measurement of the average electrical properties of a large quantity of nanowires. VC 2011 The Electrochemical Society. [DOI: 10.1149/1.3615844] All rights reserved. Manuscript submitted January 5, 2011; revised manuscript received June 28, 2011. Published July 28, 2011. Determining the average conductivity of large numbers of quasi one dimensional structures such as nanowires (NWs) and carbon nanotubes remains a challenge. The most straightforward method of determining the conductivity of NWs is by running a series of I-V measurements on a NW device with two or more electrodes. How

Amorphous oxide semiconductors have been studied primarily as the active semiconducting material for thin film transistors for active matrix display and transparent/flexible electronic applications. Recent results on printed amorphous oxide semiconductors for thin film transistors, the role of surface functionalization, and the integration of these materials for resistive random access memory applications will be described.