Article

Negative differential resistance and resistive switching behaviors in Cu2S nanowire devices

Applied Physics Letters (Impact Factor: 3.52). 01/2010; 96. DOI: 10.1063/1.3442919

ABSTRACT Two-terminal devices of Cu2S/ZnO core/shell nanowires were fabricated and measured. Forward bias sweeping produced a rectified I-V characteristic of a diode, with turn-on voltages varying from 150 to 300 mV. The turn-on voltages depended on the rate at which the bias was varied. When the bias scan was reversed, a resistive switching (RS) behavior was observed. A low-resistance state was measured, and the diode characteristic diminished. At -50 to -150 mV, negative differential resistance (NDR) was observed, after which the diode behavior was restored. This phenomenon was explained using the diffusion of Cu+ within Cu2S. ZnO acted to limit RS to the positive bias range and NDR to the negative bias range.

0 Bookmarks
 · 
46 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we report for the first time the nonlinear dynamics of three memristor based phase shift oscillators, and consider them as a plausible solution for the realization of parametric oscillation as an autonomous linear time variant system. Sustained oscillation is reported through oscillating resistance while time dependent poles are present. The memristor based phase shift oscillator is explored further by varying the parameters so as to present the resistance of the memristor as a time varying parameter, thus potentially eliminating the need of external periodic forces in order for it to oscillate. Multi memristors, used simultaneously with similar and different parameters, are investigated in this paper. Mathematical formulas for analyzing such oscillators are verified with simulation results and are found to be in good agreement.
    Microelectronics Journal 03/2012; 43(3):169–175. · 0.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a Green's function study of transport through a nano-wire in the presence of electron–electron interaction and external electric field is presented. The total Hamiltonian of the above problem is written in the tight binding approximation and Hubbard term is used to model the interaction between electrons in the central region. Our results show that in the interacting model, a conduction gap will open. Also, if the interaction between the electrons is strong enough, the negative differential resistance (NDR), which is related to the localization of charge, will not occur.
    Physica E Low-dimensional Systems and Nanostructures 04/2012; 44(s 7–8):1214–1217. · 1.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Memristive characteristics in semiconductor/metal contacts are studied by conductive atomic force microscopy. The ZnO/Au device shows excellent memristive characteristics under Pt and TiN tips and the resistances of the high-resistance state and the low-resistance state are almost unchanged with time. Unipolar resistive switching behaviour is observed when a positive voltage is applied. In addition, the pure Au film also shows resistive switching behaviour under the TiN tip which was used to test the ZnO/Au device, but this behaviour cannot be observed under a Pt tip. Our results suggest that the memristive characteristics existing in semiconductor/metal contacts are due to the formation of conducting filaments in the interior of the semiconductor and the change in the energy barrier at the interface between the conductive atomic force microscope tip and the ZnO film.
    Journal of Physics D Applied Physics 11/2011; 44(47):475102. · 2.52 Impact Factor