Low temperature transport of a charge transfer complex nanowire grown with an electric field from the vapour phase

Abstract

Suspended Cu:TCNQ (Cu-tetracyanoquinodimethane) nanowires have been grown laterally from vapour phase connecting two electrodes (∼ 1.0µm gap) with and without the presence of external electric field applied between the electrodes during growth. Temperature and bias dependent conductance of these bridged nanowires have been investigated down to 40 K. It has been found that when the nanowire is grown in an electric field, its conductance gets enhanced significantly. The nanowires show a strong non-linear conductance beyond a threshold bias along with a linear conductance at low bias. Below 100 K, the bias dependent non-linear conductance with a threshold, can be fitted to modified Zener tunneling model for charge density wave transport in both types of nanowires, raising the possibility of onset of charge density wave type transport in the Cu:TCNQ nanowires. It has been proposed that the enhancement of the conductance in Cu:TCNQ nanowires when the growth is performed in the presence of electric field occurs due to better charge transfer as well as more ordered arrangements of TCNQ stacks during growth which is enabled by strongly anisotropic polarizability of the TCNQ moiety. This also modifies the parameters related to the non-linear conductance including the threshold value.

Sustained Resistive Switching in a Single Cu:7,7,8,8-tetracyanoquinodimethane Nanowire: A Promising Material for Resistive Random Access Memory

“…This establishes essential role of the contact. This change in resistance in the body of Cu:TCNQ NW is similar to that arising from non-linear conductance in Cu:TCNQ NW recently observed 19 . The observed magnitude of change in R s may depend on nature of contact electrodes that determine the value of the exact potential drop across the length of the sample.…”

“…2 we show the resistivity data of a 65 nm diameter NW as a function of T. The temperature dependent resistivity shows 1-dimensional variable range hopping (VRH) ( ρ ∝T −1/2 ) for T ≥ 200 K (upper inset in Fig. 2 ), as is expected in this type of NWs 19 . The data shown in Fig.…”

“…At larger bias, Cu:TCNQ shows a strong non-linear conductivity (distinct from switching) which gets enhanced significantly as the temperature is lowered. At lower T, contributions from charge density wave show up leading to substantial non-linear contribution as has been demonstrated recently 19 . For determination of ρ in the LRS, we measure ρ with a current that switches it from high resistance state (HRS) to low resistance state (LRS).…”

“…FTIR was used to establish the extent of charge transfer in Cu:TCNQ from Cu to TCNQ. The details of growth and characterization of the charge transfer complex NWs are given elsewhere 19 3 0.…”

Electrofluid enhanced hydrolysis of maize starch and its impacts on physical properties

“…33 It is possible to use electric elds to improve mass transport at appropriate thermal energy. 34,35 In effect, IEF can indeed enhance the sugar yield during maize starch acid hydrolysis at appropriate temperature.…”