A bias polarity-manipulated transformation from filamentary to homogeneous resistive switching was demonstrated on a Pt/ZnO thin film/Pt device. Two types of switching behaviors, exhibiting different resistive switching characteristics and memory performances were investigated in detail. The detailed transformation mechanisms are systematically proposed. By controlling different compliance currents and RESET-stop voltages, controllable multistate resistances in low resistance states and a high resistance states in the ZnO thin film metal-insulator-metal structure under the homogeneous resistive switching were demonstrated. We believe that findings would open up opportunities to explore the resistive switching mechanisms and performance memristor with multistate storage.

We present a ZnO(1-x) nanorod array (NR)/ZnO thin film (TF) bilayer structure synthesized at a low temperature, exhibiting a uniquely rectifying characteristic as a homojunction diode and a resistive switching behavior as memory at different biases. The homojunction diode is due to asymmetric Schottky barriers at interfaces of the Pt/ZnO NRs and the ZnO TF/Pt, respectively. The ZnO(1-x) NRs/ZnO TF bilayer structure also shows an excellent resistive switching behavior, including a reduced operation power and enhanced performances resulting from supplements of confined oxygen vacancies by the ZnO(1-x) NRs for rupture and recovery of conducting filaments inside the ZnO TF layer. A hydrophobic behavior with a contact angle of ~125° can be found on the ZnO(1-x) NRs/ZnO TF bilayer structure, demonstrating a self-cleaning effect. Finally, a successful demonstration of complementary 1D1R configurations can be achieved by simply connecting two identical devices back to back in series, realizing the possibility of a low-temperature all-ZnO-based memory system.

CuOx nanowires were synthesized by a low-cost and large-scale electrochemical process with AAO membranes at room temperature and its resistive switching has been demonstrated. The switching characteristic exhibits forming-free and low electric-field switching operation due to coexistence of significant amount of defects and Cu nanocrystals in the partially oxidized nanowires. The detailed resistive switching characteristics of CuOx nanowire systems have been investigated and possible switching mechanisms are systematically proposed based on the microstructural and chemical analysis via transmission electron microscopy.

A new type of two-dimensional (2D) SnO 2 semiconductor-based gate-tunable memristor, that is, a memtransistor, an integrated device of a memristor and a transistor, was demonstrated to advance next-generation neuromorphic computing technology. The polycrystalline 2D-SnO 2 memristors derived from a low-temperature and vacuum-free liquid metal process offer several interesting resistive switching properties such as excellent digital/analog resistive switching, multistate storage, and gatetunability function of resistance switching states. Significantly, the gate tunability function that is not achievable in conventional twoterminal memristors provides the capability to implement heterosynaptic analog switching by regulating gate bias for enabling complex neuromorphic learning. We successfully demonstrated that the gate-tunable synaptic device dynamically modulated the analog switching behavior with good linearity and an improved conductance change ratio for high recognition accuracy learning. The presented gate-tunable 2D-oxide memtransistor will advance neuromorphic device technology and open up new opportunities to design learning schemes with an extra degree of freedom.

performances, including high TFT mobility (≈10 cm 2 V −1 s −1), low operation voltage (≈3 V), and low off-current characteristics as well as excellent mechanical flexibility and low-cost processability. [4] Therefore, n-channel a-IGZO-TFT is successfully commercialized in the market and widely used as a TFT backplane in the state-of-art active-matrix flat panel display such as large-sized high-resolution organic light-emitting diode and low-power consumption active-matrix liquid crystal display. [5-7] The next major challenge faced in oxide semiconductor technology is to develop complementary metal-oxide semiconductor (CMOS) inverter circuits for future ubiquitous device applications. So far, several CMOS inverters based on oxide-TFTs have been demonstrated with n-type oxide a-IGZO and p-type oxides such as SnO, Cu 2 O, and organic semiconductors. [8-10] However, different fabrication process involved in n-and p-type materials results in complicated circuit design and integration, leading to the production of the impractical circuit. [11]