Showing papers on "Organic semiconductor published in 1987"
TL;DR: In this article, a double-layer structure of organic thin films was prepared by vapor deposition, and efficient injection of holes and electrons was provided from an indium-tinoxide anode and an alloyed Mg:Ag cathode.
Abstract: A novel electroluminescent device is constructed using organic materials as the emitting elements. The diode has a double‐layer structure of organic thin films, prepared by vapor deposition. Efficient injection of holes and electrons is provided from an indium‐tin‐oxide anode and an alloyed Mg:Ag cathode. Electron‐hole recombination and green electroluminescent emission are confined near the organic interface region. High external quantum efficiency (1% photon/electron), luminous efficiency (1.5 lm/W), and brightness (>1000 cd/m2) are achievable at a driving voltage below 10 V.
13,185 citations
TL;DR: In this paper, a study of an organic polymer ferromagnetic preparation with a transition metal impurity content well below the level likely to significantly affect its magnetic properties is presented. But it is not shown that the impurity can significantly affect the magnetic properties of polymeric polymers.
Abstract: Low-dimensional, especially one-dimensional (1D), organic compounds are known to exhibit the properties of semiconductors, molecular metals and superconductors1. The theoretical prediction of 1D organic ferromagnets and the principles of construction of polymer polyradicals with a ground state spin proportional to a number of monomeric units were proposed in 1977–782,3. For nearly two decades various hydrocarbons of high spin multiplicity have been studied as the model of an organic ferromagnet4–6. Advanced quantum chemistry techniques have been applied for theoretical investigations of the electronic structure of such compounds7–9. Here we present a study of an organic polymer ferromagnetic preparation with a transition metal impurity content well below the level likely to significantly affect its magnetic properties. We find that all the organic polymer ferromagnet samples can be conditionally subdivided into three groups: paramagnetic polymers7–9, spin glasses10 and real polymer ferromagnets.
293 citations
TL;DR: In this paper, the tetrakis(alkylthio)tetrathiaful-valenes, a class of highly conductive single-component organic semiconductors, have been found.
Abstract: We have found a class of highly conductive single-component organic semiconductors; the tetrakis(alkylthio)tetrathiaful-valenes, and have given these systems the descriptive title of 'molecular fastener'1,2. In a programme to synthesize single-component molecular assemblies with high conductivity, we then discovered a new organic semiconductor, tetrakis(alkyltel-luro)tetrathiafulvalene, of electrical resistivity 8.1 x 104 Ωcm, having high charge mobility, 20–30 cm2 V–1 s–1. We explain this unusually low resistivity in terms of molecular packing and stacking manner within the crystal. The central skeleton of this compound, tetratelluro-tetrathiafulvalene moiety (C6Te4S4), is almost planar and is regularly stacked in the form of column. Along the stacking axis, tellurium atoms in neighbouring columns come close each other and form zigzag chains. The distance between those two Te atoms is 3.644(2) A, which is significantly shorter than van der Waals distance (4.12 A). It is expected that zigzag chalcogen chains formed from quasi-covalent bonds.
71 citations
TL;DR: In this article, it was shown that the Fermi levels of these two dyes lie too close together for optimum cell performance, and a synthetic version of the simple perylene dye and of ClAlPc have been prepared for stronger electronaccepting and electron-donating properties respectively.
30 citations
TL;DR: In this article, the molecular structure and physical properties of the new organic semiconductor are described along with description of frequency and temperature characteristics, life, etc. of the newly developed capacitor.
24 citations
TL;DR: In this article, the electronic, magnetic susceptibility, MS and GC-MS pyrolysis, X-ray powder diffraction, and electrical conductivity studies on metal phthalocyanine sheet polymers were discussed.
Abstract: This publication discusses the electronic, magnetic susceptibility, MS and GC–MS pyrolysis, X-ray powder diffraction, and electrical conductivity studies on metal phthalocyanine sheet polymers. The magnetic measurements over the range of magnetic field strengths 1025–6144 gauss indicated the absence of the intermolecular cooperative effect. MS and GC–MS studies indicate that all these metal phthalocyanine sheet polymers give benzene, cyanobenzene, and dicyanobenzene on thermal degradation. The electrical conductivity measurements showed that these polymers are semiconductor in nature.
19 citations
TL;DR: In this article, the first example of an organic bilayer device composed of poly(3-methylthiophene) and Prussian Blue (PB) which can be charged under irradiation and discharged in the dark reversibly was reported.
13 citations
TL;DR: In this paper, the authors describe and justify the use of a less well-known technique for synthesizing polyacetylenes and characterize the films so formed, which is of particular interest to us.
Abstract: Polyacetylenes are the simplest organic polymers which readily undergo photoablation We describe and justify the use of a less well‐known technique for synthesizing polyacetylenes and characterize the films so formed This is of interest because polyacetylenes are organic semiconductors Glow discharge polymerization yields layers around 1 μm thick Efficient ablative decomposition of polyacetylene films requires multishot exposures The role of conjugation in the chains and efficiency of the process as opposed to thermal decomposition is discussed Because the polymer contains only carbon and hydrogen, ablation in vacuum yields readily identifiable products
11 citations
01 Jan 1987
TL;DR: In this article, it was shown that a small variation of the electrochemical potential leads to a large variation in the polymer conductivity, which consequently allows the current to flow between two microelectrodes.
Abstract: Among the many areas of applications opened to organic conjugated polymers, such as polyacetylene, polypyrrole or polythiophene, a new promising field is emerging, which concerns the elaboration of organic polymer-based electronic devices. Two main characteristics of these polymers have been used for this purpose. First the possibility to switch them in a controlled way from a highly resistive neutral state to a conducting doped state. Thus, M. WRIGHTON’s group (1) has already largely shown that microelectrochemical transistors can be elaborated, in which the gate is represented by an electrochemical doping-undoping process. A small variation of the electrochemical potential leads to a large variation in the polymer conductivity, which consequently allows the current to flow between two microelectrodes. source and drain, embedded in the polymer. Even more sophisticated structures have been proposed, by the use of a solid electrolyte, leading to a solid-state device, and also by using a chemical oxidant or reductant to drive the doping-undoping process, leading thus to a chemically sensitive transistor. Although very promising, this first type of electronic devices is limited by two main factors. The channel thickness of this type of transistor being large, an important amount of charge,∿10∑7 mole e−/cm2, is needed for turning on the device, which limits the amplification power. Furthermore the channel material being a polymer, the doping process requires an ion transfer, whose slowness limits the operation frequency to some 10 Hz.
6 citations
Patent•
12 Feb 1987
TL;DR: In this paper, a novel organic electrophotographic material superior in electron transfer ability and capable of transferring positive holes in addition to electrons by using a specified compound, its charge transfer complex, and its salt as an organic semiconductor.
Abstract: PURPOSE:To obtain a novel organic electrophotographic material superior in electron transfer ability and capable of transferring positive holes in addition to electrons by using a specified compound, its charge transfer complex, and its salt as an organic semiconductor. CONSTITUTION:The organic electrophotographic material to be used is represented by the formula shown on the right in which X of the side chain is dicyan, CHCN, diester, N-CN, or CHCO2R1; one of the hetero rings A and B is alkyldiazole, alkylisoxazole, alkylisodiazole, dialkylisodiazole, dialkyldioxane, or alkylisothiazole; and the other of them may be alkylbenzene when said one of them is a hetero ring. Said compound of the formula is synthesized generally from the corresponding quinone derivative. This compound forms the charge transfer complex with an electron donor, and this complex can be used as the organic electrophotographic material, and the anion of this compound and the salt of its anion radical can be also used as the organic semiconductor.
5 citations
Patent•
02 Oct 1987
TL;DR: In this article, the main metal of metal phthalocyanine is selected, for example, from Cu, Al, Co, Zn, Li, Fe, Ni, V, Mn, and Ru.
Abstract: PURPOSE:To realize a memory element using organic semiconductor by holding an organic semiconductor of phthalocyanine thin film coordinating metal atoms with metals of different work functions CONSTITUTION:An element is formed by holding the phthalocyanine thin film 3 coordinating metal atoms as an organic semiconductor with two kinds of metal electrodes 2, 4 in different work functions The main metal of metal phthalocyanine is selected, for example, from Cu, Al, Co, Zn, Li, Fe, Ni, V, Mn, and Ru Moreover, as a metal used for the electrodes, two kinds of metals in different work functions are selected, for instance, from Au, Ag, Al, Ti and In, etc For example, a thin film 2 of Au is formed, by the electron beam vacuum deposition, to a part of slide glass 1 in the thickness of 200nm using a mask Next, a copper phthalocyanine thin film 3 is formed by the resistance heating vacuum deposition method using a mask in the thickness of 200nm Moreover, a titanium thin film 4 is also formed by the electron beam vacuum deposition method as the surface electrode
TL;DR: In this article, the first example of an organic bilayer device composed of poly(3-methylthiophene) and Prussian Blue (PB) which can be charged under irradiation and discharged in the dark reversibly was reported.
Abstract: A photochargeable device which can be charged under irradiation and discharged in the dark should open a new field of photoenergy conversion and storage. Such a device can be used also for information storage. Such a device can be used also for information storage. Some model cells for photoenergy conversion and storage have been constructed by using liquid-junction inorganic semiconductors in contact with a redox electrolyte solution [l-5]. Recently, organic semiconductors such as poly(acetylene) [6,7], poly(pyrrole) [&lo], poly(aniline) [ll], and poly(thienylene) [12,13] were reported to give photocurrents in the form of a Schottky type device. Although the light-to-electricity conversion efficiency of these organic semiconductor devices is inferior to that of inorganic semiconductor ones, they have merits in their easy fabrication, utilization as a film, and fairly high stability, except for poly(acetylene), in contrast to the corrosive narrow bandgap inorganic semiconductors. Prussian Blue (PB) is a polynuclear iron cyanide complex with the composition, Fe~‘[Fe”(CN),]~-. The electrochemical behavior of PB has been well characterized [14-161. Since PB is both oxidized and reduced reversibly, it can work as both the anode and cathode active material of a secondary battery [17-191. PB can be used as a fihn because of its high molecular weight structure. The photoelectrochemical reaction of a PB film coated on a TiO, liquid-junction photoanode was reported in ref. 20. In the present paper we will report the first example of an organic bilayer device composed of poly(3-methylthiophene) and PB which can be charged under irradiation and discharged in the dark reversibly.
01 Jan 1987
TL;DR: In this article, the potential for using such materials as polymeric organic semiconductors or as surface-bound electrocatalysts is considered, and factors influencing charge separation at a semiconductor:electrolyte interface and on metal coordination polymers are delineated.
Abstract: Electrochemical features of model complexes for a new class of nickel:tetrakis (dialkylphosphino) benzene coordination polymers are described. The potential for using such materials as polymeric organic semiconductors or as surface-bound electrocatalysts is considered. Factors influencing charge separation at a semiconductor:electrolyte interface and on metal coordination polymers are delineated.