Search

The fabrication of memory devices based on the Ag/PMMA:Na/Ag structure and their electrical characteristics are reported. The Ag/PMMA:Na/Ag devices show a hysteresis behavior with different Na contents. The most evident hysteresis behavior for memory effect, represented as the on/off current ratio, is found to be as high as 105 in Ag/PMMA:Na-180 s/Ag devices. The carrier conduction mechanisms between the high and low resistance states and the transition states are further examined on the basis of trap-assisted space charge limited current theory. Such devices sustain at least 60 operation iterations and 100 s duration tests. Hence, the idea of incorporating Na particles into the organic layer of memory devices creates a promising direction for the development of organic memory devices.

The linear-regime transfer properties of the annealed pentacene-based organic thin film transistors (OTFTs) in air at various temperatures up to 375K are examined. It is found that the linear-regime carrier mobility increases with increasing annealing temperature reaching a maximum at 350K, and then decreases with further increasing of annealing temperature beyond that point. However, an increase in annealing temperature leads to the shift of the threshold voltage towards positive gate-source voltages. An analysis through the temperature-dependent transfer characteristics of OTFTs reveals that the increased carrier mobility is the result of the reduced values of the hopping distance and the barrier height for hopping. Display Omitted The thermal annealing effect on carrier transports in pentacene is researched.The linear-regime carrier mobility is increased by thermal annealing at 350K.The temperature-dependent transfer characteristics exhibit the hopping behavior.Annealing leads to a change in the hopping conduction behavior.Annealing leads to the reduced values of hopping distance and barrier height.

The effect of a metallic front gate on the temperature-dependent electronic property of pentacene films was investigated in this study. The carrier mobility exhibits strong temperature dependence, implying the dominance of tunneling (hopping) at low (high) temperatures. The room-temperature mobility was drastically increased by capping an In (Au) layer on the pentacene front surface. However, the carrier concentration is not affected. An increase in the phonon energy occurs for In-capped or Au-capped pentacene samples, which corresponds to the abrupt transition to the nonlocal electron–phonon coupling. The enhanced mobility by capping a metal layer is attributed to a change in the electron–phonon coupling.

This study investigates the effect of different types of SiO 2 on the electronic and surface properties of pentacene films. Developing better contacts on dielectrics is one of the main challenges for pentacene-based transistor technology. The water contact angle variation indicates more hydrophobic thermally grown SiO 2 surfaces than sol–gel SiO 2 surfaces, suggesting that the thermally grown SiO 2 dielectric enables a better molecular arrangement as the pentacene layer is deposited. It is found that the carrier mobility in pentacene on thermally grown SiO 2 dielectrics is higher than that in pentacene on sol–gel SiO 2 dielectrics. The Hall-effect analysis by using the polaron theory revealed that the enhanced carrier mobility is due to the increased spacing between molecules.

In this study, the effect of the incorporation of ZnO nanoparticles into poly(3-hexylthiophene) (P3HT) on photocurrent of P3HT/n-type Si diodes was examined. Charge detrapping/trapping phenomena are studied through time domain measurement for P3HT-based diodes and thin-film transistors. Hole detrapping was the dominant phenomena in P3HT (ZnO-doped P3HT) films. For higher density of ZnO, more holes can be released and induce higher photosensitivity of the device. ZnO influences the photoresponse by providing additional holes that serve to reduce the photocurrent time constant.