Abstract
Resistive switching (RS) devices are widely believed as a promising candidate for next generation nonvolatile resistance random access memory. Here, Zn2SnO4-sheathed ZnO core/shell heterostructure nanowires were constructed through a polymeric sol–gel approach followed by post-annealing. The back-to-back bipolar RS properties were observed in the Ohmic contact two-terminal devices based on individual core/shell nanowires. With increasing bias to about 1.5 V, it changes from high-resistance states (HRS) to low-resistance states, and however, it can be restored to HRS by reverse bias. We propose a new mechanism, which is attributed to the injection of electrons into/from interfacial states, arising from the lattice mismatch at ZnO/Zn2SnO4 heterointerface. Upon applying negative/positive voltage at one end of devices, where interfacial states are filled/emptied, barrier will be eliminated/created, resulting into symmetric RS characteristics. The behavior of storage and removal charges demonstrates that the heterostructures have excellent properties for the application in resistance random access memory.
Highlights
Resistive switching (RS) devices are widely believed as a promising candidate for generation nonvolatile resistance random access memory
The X-ray diffraction (XRD) pattern [Fig. 1(a)] of the as-grown product presents clear evidence that the nanostructures are composed of two crystalline phases, that is, diamond-cubic Zn2SnO4 (JCPDS file: 24-1470) and wurtzite-hexagonal ZnO (JCPDS file: 36-1451)
From the resistance change, the RS behavior of the memory cell seems to exhibit a quasi-unipolar RS nature since the device can both be switched to the low resistance state (LRS) in the two different directions of nanowirebased memory cell
Summary
Resistive switching (RS) devices are widely believed as a promising candidate for generation nonvolatile resistance random access memory. The RS behavior originates from repeated resistance changes between high resistance state (HRS) and low resistance state (LRS), and is controlled by an external electrical field with opposite polarity This type of memory devices, generally composed of metal-insulator-metal structures, has many merits for applications such as high-density, high-speed, and lowpower consumption. The RS phenomena have been observed in a variety of materials such as transition metal oxide (TMO)[1,2,3,4,5,6,7], perovskite oxide[8,9,10,11,12], and organic polymers[13] Some mechanisms, such as formation/rupture of conducting filament[14,15,16], alteration of Schottky barrier[17], migration of oxygen vacancies[18,19], trapping/detrapping of charge carriers[20,21], and Mott transition[22], have been introduced to explain the origin of RS properties. In comparison with single oxides, composite oxides can form heterojunction, which have more freedom to tune the physical properties of the heterostructure by selecting the materials with different energy bands
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
