Duality in Resistance Switching Behavior of TiO₂-Cu₂ZnSnS₄Device

Abstract

The resistive switching behavior of TiO 2 based electronic devices have been extensively investigated the last two decades due to their low cost and potential applications in high speed electronic devices. However, the randomness in switching behavior and uncertainty in conducting filament formation often restricts their usage for long-term applications. A duality in current transport mechanism was observed when nano-architectural parameters of the TiO 2 memory resistance device were altered. TiO 2 nanotube-CZTS nanocrystals based devices exhibit Fowler-Nordheim quantum tunneling, whereas TiO 2 nanocrystals-CZTS thin film based devices exhibit space charge limited conduction. Temperature dependent electrical studies indicate that polaronic transport is one of the phenomena assisting in electrical conduction. Electronic band information suggests that tunneling between CZTS and TiO 2 is indirect. A unique interface state between two adjacent materials seems to be responsible for the negative differential resistance (NDR) behavior of Low cost electrical bistability due to nonlinear conducting behavior has been an exciting area of research in recent years. [1][2][3][4][5][6][7][8] Several new devices such as tunnel diodes, multivibrators, and organic bistable systems have been investigated.1-7 Some of these devices possess unique I-V characteristics and non-conventional current transport mechanisms. Devices showing negative differential resistance (NDR) can be utilized for various low power applications such as radio frequency, logic and neuromorphic devices, fast switching, and high frequency oscillators.1-7,9-11 Materials such as carbon nanotubes, graphene, and conducting polymers have been recently utilized for room temperature NDR behavior or memory resistance applications. [1][2][3][4][5][6][7]9,10,12,13 Memory resistors can be fabricated using semiconductors and metal oxides such as Nb 2 O 5 , NiO, ZnO and TiO 2 .14 Thin film memory resistors offer advantages such as high switching speed and low energy electroforming. The use of thin film TiO 2 in a memory resistor has demonstrated potential dependent on/off switching when sandwiched between two platinum contacts. 15 It is generally believed that a memoresistance effect in TiO 2 nanostructures is based on the mobility of vacancies or defects. [15][16][17] The conduction mechanism is based on the formation and transport of conducting filament (CF). A conducting filament generally consists of oxygen vacancies that form or break due to electric field driven migration. Because of randomness and uncertainty in CF's formation, resistance-switching (RS) devices often perform randomly and thus have less control over operating parameters. Another report suggests that Joule heating is also a major cause for current controlled negative resistance behavior. 18 This behavior relies on polaronic transport in TiO 2 . In polaronic transport, the hopping motion of small polarons up to certain temperatures influences conduction. Several other mechanisms and switching modes such...

Conducting-insulating transition in adiabatic memristive networks

“…Through simulations we obtain current-voltage (I-V) curves for various values of the G on /G of f ratio and discuss the features implied by the adiabatic limit. The I-V curves found show a duality between forward and reverse switching processes that has been observed in several experimental systems [16,17] and clarifies the role of boundary conditions in the network. These features are captured by a mean-field theory and cluster approximation which clarify the internal dynamics and account for the features of the I-V curves.…”

“…Running the model in the current controlled setting thus gives nearly identical results, but exchanges the fluctuating region in the reverse direction for the discrete jump in the forward direction. It is important to note that this connection between the forward and reversed hysteresis loops has been observed experimentally in individual memristive systems [16,17] as well. While observing the duality for a network of resistors is clear, the extension to the dynamic non-linear elements considered here is surprising, especially when considering the asymmetry in the switching process between the forward and reversed directions, one of which corresponds to a backbone forming along the direction of current propagation, and the other corresponding to a crack forming transverse to the current flow.…”

Augmented Z scheme blueprint for efficient solar water splitting system using quaternary chalcogenide absorber material

“…Titania nanotubes were synthesized by electrochemical anodization of titanium foils (0.1016 mm thick, ESPI metals, G1 grade) using a previously reported method. 48,49 Titanium foils were cut into 1.5 Â 1.5 cm coupons, hand-polished with emery paper, and degreased in an acetone-isopropanol (50% v/v each) mixture by ultrasonicating for 30 minutes. Anodization was carried out at 30 V in a fluorinated ethylene glycol solution (0.…”

Geometrical modifications and tuning of optical and surface plasmon resonance behaviour of Au and Ag coated TiO2 nanotubular arrays

“…Such three modes were obtained at $395 cm À1 (B 1g ), 516 cm À1 (A 1g ) and 640 cm À1 (E g ), respectively and they correspond well with earlier reported Raman spectra of TiO 2 . 32 It is interesting to observe that Raman intensity of irregular shaped titania nanotubes are stronger compared to straight or vertically grown TNT arrays. One possible explanation of such behaviour can be attributed to the difference in thickness of TNT arrays.…”