Electrical characterisation of M/I/M structures incorporating thin layers of 22-tricosenoic acid deposited on noble metal base electrodes

Abstract

New techniques for fabricating Ag/LB/Mg structures have been developed which yield structures having insulating properties in the absence of metal oxide layer. This has allowed an original study of the conduction processes through multilayers of 22-tricosenoic acid down to a thickness of only a bilayer of this material. The room temperature conductance G was found to be independent of frequency from 0.001 to 0.1 Hz, but changed to a G( omega ) varies as f0.7 dependence for higher frequency signals from 10 to 105 Hz. The low- and high-bias results showed a change in the conduction mechanism with change in layer thickness, associated with possible differences in the LB structure between the first and subsequently deposited monolayers. The high-bias results for greater than six monolayers showed that the logarithm of the current was proportional to the square root of the voltage, characteristic of a Schottky or Poole-Frenkel mechanism. Assuming a Schottky mechanism to describe this dependence the height of the insulating barrier was calculated to be 1.06+or-0.04 V.

PACAP mRNA is expressed in rat spinal cord neurons

“… Chemical structures of unimolecular rectifiers. The Schottky‐barrier or “S” rectifier DDOPCBHTCNQ, 2 [refs 39,48]. The first confirmed molecular rectifier, 3 [refs 16–20], a related zwitterionic or betaine molecule 4 [ref 50].…”

Molecular rectifier

“…Initially, simple metal/Langmuir-Blodgett multilayer/ metal (M/LB/M) junctions were fabricated using a similar planar geometry to that used by Geddes et al [8][9][10]. They reported that G)-tricosenoic acid multilayers interposed between silver and magnesium electrodes exhibited J/V characteristics which were nonlinear at larger applied biases, obeying lnC/)ocF 1/4 for junctions of four monolayers thickness or less and lnC/)ocK 1/2 for more than six monolayers.…”

Electrical Properties of a Novel 1,3-Bis-(<I>p</I>-Iminobenzoic Acid) Indane Langmuir-Blodgett Films Containing ZnS Nanoparticles

“…However similar anomaly, i.e., larger current in thicker LB sample, is also reported by Geddes et al for 22-tricosenoic acid LB multilayer films. 24 In order to explain the electronic conduction process through LB films and the effect of the ZnS nanoparticles on conductivity, lnJ versus V 1/2 has been replotted in Figure 7 for all studied sample in the voltage range that corresponds to the exponentially increasing current. The relation between lnJ and V 1/2 shows rather linear dependence.…”

“…Geddes et al have calculated the barrier height of 22-tricosenoic acid LB films grown with various thicknesses on different substrates and fabricated in a M/I/M structure using a similar approach 24. From the…”