We report the first organic light-emitting field-effect transistor. The device structure comprises interdigitated gold source and drain electrodes on a Si/SiO(2) substrate. A polycrystalline tetracene thin film is vacuum sublimated substrate forming active layer of device. Both holes electrons are injected from contacts into this leading to electroluminescence tetracene. output characteristics, transfer optical emission properties reported. possible mechanism for electron injection suggested.

In this study, the optical properties of nanocrystalline europium doped yttria, Y2O3:Eu3+ were investigated in dependence on different caging hosts such as porous MCM-41, silica, and alumina with pore sizes ranging between 2.7 to 80 nm. These results compared nanopowders measured air aqueous solution whose particle 5 nm 8 nm, respectively. All these a commercial lamp phosphor powder grain size about μm. The structural samples determined by x-ray diffraction transmission electron microscopy....

A dynamical model of the temporal dependence photostimulated luminescence storage phosphor BaFBr:Eu2+ as a result preceeding x-ray irradiation is presented. The based on monomolecular recombination mechanism. commonly used bimolecular mechanism leads to contradictions with experimental observations. explained by existence photostimulable complex center and an electron trap in close proximity. Charge transfer after optical excitation occurs through tunneling. simulation transient charge...

The mechanisms of enhanced electron injection into the transport layer Alq3 [tris(8-hydroxyquinoline)-aluminum] via LiF interlayers are studied by means I–V characteristics, secondary ion mass spectroscopy (SIMS), and Kelvin probe measurements. Devices for single carrier were prepared using aluminum electrodes, layers, thin intermediate layers LiF. It was found that devices deposited in order Alq3-LiF-aluminum have a much higher capability than structures aluminum-LiF-Alq3. SIMS depth...

Discotic molecules comprising a rigid aromatic core and flexible side chains have been promisingly applied in OLEDs as self-organizing organic semiconductors. Due to their potentially high charge carrier mobility along the columns, device performance can be readily improved by proper alignment of columns throughout bulk. In present work, was increased 5 orders magnitude due homeotropic columnar ordering induced boundary interfaces during thermal annealing mesophase. State-of-the-art diodes...

Abstract Ferroelectrets have promoted a variety of exciting flexible sensors, actuators, and microenergy harvesters. However, most ferroelectrets been fabricated from non‐degradable petro‐based resins, thus the recycling these materials constitutes big challenge. This article reports biodegradable bioabsorbable ferroelectret films made polylactic acid (PLA) resins for highly sensitive transducer applications, which can operate either in piezoelectric 33 or 31/32 mode. By modification...

The knowledge about properties of electronic traps in organic semiconductors is one the major keys for understanding and optimization charge transport devices. In present article density occupied states most prominent pristine small molecule systems selected polymers are reported determined, by fractional thermally stimulated current luminescence techniques. order to distinguish between impurity structurally based traps, model doped as well differently deposited layers were studied....

Control over spatial positioning of CdSe quantum dots(QDs) is a very important criterion for device fabrication. These authors utilize the ordered array pores provided by mesoporous material MCM-41 to achieve this. TEM single CdSe@MCM-41 particle (see Figure) shows that hexagonally mesostructure still intact after growth nanoparticles inside mesopores.

Photostimulable x-ray-storage phosphors in the form of image plates are one most important applications defect centers ionic crystals. Understanding underlying mechanism, apart from its practical relevance, creates additional insights into generation and kinematics radiation defects this class materials. In paper commercial storage phosphor BaFBr:${\mathrm{Eu}}^{2+}$ is investigated. It shown that x-ray irradiation produces both fluorine bromine F centers, aggregates thereof. Only were found...

An ambipolar pentacene transistor with top-gold and top-calcium contacts has been realized by utilizing a parallactic shadow mask effect during vapor deposition. The deposited on top of silicon dioxide gate insulator is doped Ca at the pentacene/SiO2 interface in order to compensate electron traps. equivalent circuit model based resistor-capacitor network developed describe basic electrical properties transistor. Shockley-like analytical expressions for output transfer characteristic, as...

Temporal behavior of ferroelectric ceramics during the polarization switching cannot be satisfactorily explained by simple Debye or even stretched exponential laws. These materials exhibit rather a wide spectrum characteristic times interpreted different authors as nucleation waiting times, physical reasons for time distribution still remaining unclear. A new model presented here suggests that variance in ferroelectrics originates from random local electric fields due to intrinsic randomness...

Abstract Universal scaling features of polarization switching are established experimentally in rather different classes disordered ferroelectrics: well‐studied lead‐zirconate titanate (PZT) ferroelectrics, recently synthesized Cu‐stabilized 0.94(Bi 1/2 Na )TiO 3 –0.06BaTiO (BNT‐BT) relaxor and classical organic ferroelectrics P(VDF‐TrFE). These properties explained by an extended concept inhomogeneous field mechanism (IFM) dynamics ferroelectrics. Accordingly, exhibit a wide spectrum...

The electrical responses of a columnar liquid crystal (a diimidodiester derivative benzo[ghi]perylene) deposited either by spin-coating or thermal evaporation into typical OLED device are compared. For the spin-coated film, homeotropic alignment was induced annealing, which enhanced charge carrier mobility significantly. evaporated films, could not be obtained annealing. However, degree rectification higher than 3 orders magnitude achieved, even without with an response similar to aligned...

The buildup of air-breakdown-induced polarization in a one-side-metallized three-layer sandwich structure consisting fluorinated ethylene propylene copolymer (FEP) / expanded polytetrafluoroethylene (ePTFE) FEP has been studied utilizing corona triode for voltage application. layers form structurally and electrically dense layers, whereas the ePTFE layer consists 91% air 9% fibrous PTFE. Upon negative charging, breakdown sets within pores ePTFE, as soon electric field strength exceeds...

We report on light emission from a polymeric transistor that utilizes interdigitated source and drain electrodes with channel length of 5 μm in bottom gate configuration based Si/SiO2 substrate. The polymer investigated is poly[9,9-di(ethylhexyl)fluorene] deposited by spin coating chloroform solution to achieve an active layer thickness 40 nm. Light occurs above voltages −60 V the intensity can be controlled voltage. Emission close electrode as determined optical microscopy. operates hole...

The realization of an n-type pentacene field-effect transistor based on interface-doped is demonstrated, laying a headstone for organic complementary-metal–oxide–semiconductor technology. doping performed by depositing traces calcium onto the gate insulator before applying semiconductor. Electron mobilities 0.19cm2V−1s−1 are achieved. field effect, i.e., electron accumulation behavior, studied impedance spectroscopy and charge measurements metal–insulator–semiconductor (MIS) diode. A good...

Relative charge-density distributions in the thickness direction of thin (>10μm) polymer films are determined directly and accurately with a new laser-induced pressure-pulse (LIPP) method: A pressure pulse is generated sample by applying short (70ps) energetic (1-11mJ) light from Nd:YAG laser to specially coated surface sample. Stress effects within this layer possibly recoil caused ablation some target material generate desired less than 1ns duration which propagates through From electrode...

In this paper we examine the stability of corona- and electron-beam-charged 25-μm FEP-A in open circuit by using thermally stimulated (TSC) measurements. We show that electrets charged with electron beams 10 keV or higher are more stable than corona-charged foils. The inferior samples is due to filling surface traps as opposed volume samples. A peak at 155 °C was attributed located a depth 0–0.5 μm, while 170 charge stored 0.5–1.8 μm beneath nonmetallized surface. yield 200 °C. total trap...

Several experiments were performed in order to understand the creation and readout mechanisms of photostimulable (PS) centers BaFBr:${\mathrm{Eu}}^{2+}$ single crystals. PS can be efficiently created starting from 6.7 eV, i.e., minimal energy required excite first valence exciton. This exciton relaxes an e-${\mathit{V}}_{\mathit{k}}$ (${\mathrm{Br}}_{2}^{\mathrm{\ensuremath{-}}}$) pair. The relaxation such a defect neighborhood ${\mathrm{Eu}}^{2+}$ yields center, namely, F-H An additional...

The dynamics of polarization switching in a soft lead-zirconate-titanate ceramic has been studied over broad time window ranging from 10−6–106 for applied fields between 0.5 and 2.5 kV/mm. classical Kolmogorov–Avrami–Ishibashi model the reversal was not able to satisfactory explain obtained results. Therefore, new concept ferroelectric ceramics suggested, which is based on two principal assumptions, (1) strong dependence local electric field (2) random distribution times caused by an...

Polymers with electrically charged internal air cavities (ferroelectrets) reveal a pronounced piezoelectric response and are regarded as soft electroactive multi-functional materials. This work presents preliminary results on the preparation effect of ferroelectrets based polylactic acid (PLA) polymer. A distinctive feature manufactured films is that they biodegradable. After microstructure modification carbon dioxide (CO2) foamed PLA sheets by hot-pressing treatment corona polarization,...

Filling the pores of molecular sieves is a way to achieve regular nanoscale arrays materials at drastically reduced production costs. The loading zeolite MCM-41with semiconductor GaN reported here for first time using triazidogallium precursor shown in Figure. process and subsequent conversion into are thus possible non-aqueous medium can be conveniently followed by IR.