Showing papers on "Organic semiconductor published in 1985"
TL;DR: In this article, the authors demonstrate that high charge carrier mobility is an inherent property of organic molecular crystals at low temperatures and demonstrate that charge carrier transport measurements are a sensitive tool for the analytical characterization of high purity organic molecular crystal.
Abstract: This contribution demonstrates that high charge carrier mobility (<400 cm2/Vs) is an inherent property ofultrapure organic molecular crystals at low temperatures Small concentrations of traps, however, can completely obscure these microscopic transport properties on macroscopic scales We describe extensive purification procedures with naphthalene and perylene, which led to the observation of high mobilities At the same time we demonstrate that charge carrier transport measurements are a sensitive tool for the analytical characterization of high purity organic molecular crystals
197 citations
TL;DR: In this paper, a vapor-sensing method has been developed which is compatible with monolithic silicon microelectronics technology, and electronic conductance changes caused by vapor interactions with very thin films of organic semiconductors are shown to be sensitive, reproducible, rapid and stable chemical detectors.
Abstract: A vapor-sensing method has been developed which is compatible with monolithic silicon microelectronics technology. Specifically, electronic conductance changes caused by vapor interactions with very thin films of organic semiconductors are shown to be sensitive, reproducible, rapid, and stable chemical detectors. Functionalized copper phthalocyanine multilayer films deposited by the Langmuir-Blodgett technique onto planar microelectrode arrays can easily detect ammonia at sub-ppm concentration levels.
116 citations
Patent•
30 Sep 1985
TL;DR: In this paper, a layer of organic semiconductor is disposed between two electrodes which, in turn, are connected to a voltage source, and a chemoresistive gas sensor is provided which has improved sensitivity.
Abstract: A chemoresistive gas sensor is provided which has improved sensitivity. A layer of organic semiconductor is disposed between two electrodes which, in turn, are connected to a voltage source. High conductivity material is dispersed within the layer of organic semiconductor in the form of very small particles, or islands. The average interisland spacing is selected so that the predominant mode of current flow is by way of electron funneling. Adsorption of gaseous contaminant onto the layer of organic semiconductor modulates the tunneling current in a quantitative manner.
64 citations
TL;DR: In this paper, N-docosylpyridinium-TCNQ-iodine ternary salts were used to conduct Langmuir-Blodgett films with reasonably low resistivity (10-50 Ω cm).
41 citations
TL;DR: In this article, thin films of the organic compound 3,4,9,10−perylenetetricarboxylic dianhydride (PTCDA) were deposited on n and p-type GaAs substrates, and were found to form high contact barriers.
Abstract: Thin films of the organic compound 3,4,9,10‐perylenetetracarboxylic dianhydride (PTCDA) were deposited on n‐ and p‐type GaAs substrates, and were found to form high contact barriers. Barrier energies of 0.64 eV on n‐type substrates and 0.75 eV on p‐type material yielded organic‐on‐inorganic (OI) contact barrier diodes characterized by exponentially increasing forward current with voltage, and a reverse dark current leakage limited by generation and recombination of carriers in the GaAs bulk. The Fermi level does not appear to be pinned at the OI interface, contrary to what is commonly observed in metal/GaAs Schottky barrier diodes. In addition, we have made OI contact barriers using N,N’‐dimethyl 3,4,9,10‐perylenetetracarboxylic diimide (DIME‐PTCDI) deposited on n‐ and p‐type GaAs. These devices have contact barriers of 0.85 eV for substrates of either majority‐carrier‐type. The n values obtained from the forward biased characteristics of the GaAs/DIME‐PTCDI structures are n=1.19, and are the lowest obtai...
29 citations
TL;DR: In this paper, the spectral cosensitization effect of photoelectrochemical and photovoltaic systems with organic p-n junctions was investigated. And the p-p photoelectrones lead to a better spectral match with a solar spectrum than the Schottky barrier type cells for either of the organic compounds.
Abstract: Organic photoelectrodes based on p-p iso-type junctions are found to exhibit a spectral cosensitization effect, which has already been reported for photoelectrochemical and photovoltaic systems with organic p-n junctions. The p-p photoelectrodes lead to a better spectral match with a solar spectrum than the Schottky barrier type cells for either of the organic compounds. A mechanism different from that for the organic p-n assemblies is proposed to account for the photocurrent enhancement at the organic photoelectrodes based on p-p iso-type junctions. 20 references, 4 figures.
18 citations
Patent•
21 Aug 1985TL;DR: In this paper, a method of monitoring gases using electronic conductivity changes in ordd organic semiconductor films comprising an insulated substrate fabricated to an interdigital microelectrode and coated with a vapor sensitive semiconductor film was proposed.
Abstract: A method of monitoring gases using electronic conductivity changes in ordd organic semiconductor films comprising an insulated substrate fabricated to an interdigital microelectrode and coated with a vapor sensitive semiconductor film. Variations in current flow caused by vapors interacting with the film are indicative of the vapor type.
16 citations
TL;DR: In this article, it was shown that the time-of-flight mobilities obtained with suitable members of the family of organic photoconductors such as naphthalene and perylene also represent the basic transport processes occurring in organic semiconductors and conductors.
Abstract: Are the time-of-flight mobilities obtained with suitable members of the family of organic photoconductors such as naphthalene and perylene also representative of the basic transport processes occurring in organic semiconductors and conductors? Our recent results support this idea.
13 citations
Patent•
05 Apr 1985TL;DR: In this paper, the additive is selected from polyhydric alcohols, saccharides, and fine powder of metals such as iron, nickel and cobalt, which is used to suppress the evolution of a toxic gas such as HCN.
Abstract: Organic semiconductor compositions comprising CN group-bearing semiconductive salts and an additive capable of suppressing evolution of a toxic gas such as HCN upon excessive heating of the salts. The additive is selected from polyhydric alcohols, saccharides, and fine powder of metals such as iron, nickel and cobalt. Solid electrolytic capacitors using the organic semiconductor compositions are also described.
13 citations
TL;DR: In this article, the electrical behavior of cells where is a blocking electrode (In or Al) was investigated in a wide frequency range (10 −3 − 10 5 Hz). And the role of atmospheric oxygen in the contact properties was pointed out, the contact being 'ohmic' when the sample is very pure.
8 citations
TL;DR: In this paper, the peculiar character of two single component organic semiconductors, cytochrome c3 and tetrabenzopentacene, is described and a survey of organic semiconductor properties is presented.
Abstract: Historical survey of organic semiconductors is presented. The peculiar character of two single component organic semiconductors, cytochrome c3 and tetrabenzopentacene, is described.
TL;DR: In this paper, the suitability of organic-on-inorganic (OI) contact barrier diodes for use in deep level transient spectroscopy (DLTS) of III-V semiconductors was investigated.
Abstract: We have investigated the suitability of organic‐on‐inorganic (OI) semiconductor contact barrier diodes for use in deep level transient spectroscopy (DLTS) of III‐V semiconductors. The diodes are formed by vacuum deposition of a thin film of an organic molecular solid onto semiconductor samples as has been previously reported. DLTS measurements performed on n‐type GaAs using conventional Au Schottky barriers have been compared with those using OI diodes DLTS measurements have also been made on as‐grown p‐type GaAs and n‐type InP (upon which high quality conventional Schottky barriers cannot readily be fabricated) using OI diodes. OI devices can be made upon many semiconductors for which conventional Schottky barriers cannot be fabricated, require no sample heating, and can be easily removed without detrimental effects to the inorganic semiconductor material.
TL;DR: In this article, a technique for producing good quality well-defined anthracene-doped thin films of the organic semiconductor Cs 2 TCNQ 3 (TCNQ ≡ 7,7,8,8-tetracyanoquino-dimethane) is described.
Patent•
30 Sep 1985
TL;DR: In this paper, an n-type semiconductor, such as SiC, Si, etc., is employed as an electron injection electrode, thus increasing electron injection efficiency, and a straight chain fatty acid is added as a substituent.
Abstract: PURPOSE:To improve electron injection efficiency to an LB film as an emitter, and to obtain high luminous efficiency by using an n-type semiconductor as an electron injection electrode. CONSTITUTION:An n-type semiconductor 1, such as SiC, Si, etc., electron affinity thereof extends over 4eV or less, is employed as an electron injection electrode, thus increasing electron injection efficiency. Materials for an LB film 2 consisting of a condensed polycyclic aromatic compound, such as naphthalene, anthracene, perylene, pyrene, etc. and derivatives thereof, pigments, such as coumarin, rhodamine, kiton red, phthalocyanine, quinacridone, etc. and derivatives thereof or a polymer, etc., with hetero atoms, such as polypyrrole, polyindole, polyphenylene, polyaniline, polyvinyl carbazole, etc., can be cited as an organic semiconductor material used as an emitter. These organic semiconductors can easily be changed into the LB film by adding a straight- chain fatty acid as a substituent.
TL;DR: In this paper, thermally-stimulated currents (TSC) with sharp spectra were observed in tetracene films, which were deposited at room temperature and cooled rapidly after deposition.
Abstract: Thermally-stimulated currents (TSC) with sharp spectra were observed in tetracene films deposited at room temperature and cooled rapidly after deposition. A TSC near 230 K was observed to depend on the film thickness, the existence of a bias voltage, the excitation wavelength, and the photocurrent, and appeared only in a vacuum. This TSC is thought to be due to an amorphous structure in the films. Its behavior shows that it is produced by charge-transfer excitons interacting with charge carriers. As the amorphous structure disappeared, polycrystallization occurred in the films.
Journal Article•
Patent•
10 May 1985
TL;DR: In this paper, the oxide polymer of an aniline compound is a substantially linear polymer, wherein a quinonedimine structure basically expressed by a formula in the Figure is a main repeating unit.
Abstract: PURPOSE: To obtain a Schottky bonding element, by utilizing the fact that the oxide polymer of an aniline compound is a P-type organic semiconductor having very stable electric characteristics in air, and depositing a specified metal layer. CONSTITUTION: The oxide polymer of an aniline compound is a substantially linear polymer, wherein a quinonedimine structure basically expressed by a formula in the Figure is a main repeating unit. When an electron acceptor as a dopant is included, conductivity is indicated. The dopant is not restricted if it is a proton supplying material. Halogen, sulfuric acid, methanol and the like are used. A macromolecular weight body is desirable for the polymer. It is suitable when the dopant has the weight of 0.5g/dl and 97% concentrated sulfuric acid solution has the logarithmic viscosity of 0.1∼1.0 at 30°C. When, one of Al, In and Ga is evaporated on the surface of the P-type organic halogen of such a polymer in a vacuum, the stable Schottky bonding element having excellent rectifying property is obtained. In detail, a P-type organic semiconductor 3 is provided on an Au electrode 2 on a glass substrate 1 so that a part of the semiconductor is exposed. A specified metal 4 is laminated on the surface, and a Pt leads 5 are attached thereto. COPYRIGHT: (C)1986,JPO&Japio
TL;DR: In this paper, conductivity and thermopower data of pure and irradiated samples are presented and discussed together with the E.S.R. data for N-methyl-derivatives of pyridinium with TCNQ.
Abstract: N-Methyl-derivatives of pyridinium with TCNQ are organic semiconductors with a gap of 0.6 eV approximately.In the pure materials the partially compensated semiconductor model explains yery well the main features of the transport properties. But this model cannot explain the whole set of results especially the magnetism of these compounds. In this paper conductivity and thermopower data of pure and irradiated samples are presented and discussed together with the E.S.R. data.