Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 9283-9290 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A model has been developed for charge recombination in double-layer organic light-emitting diodes (LEDs) in which charge transport across the interface between the anodic and cathodic cell compartments is impeded by energy barriers. Current flow is assumed to be controlled by the interplay between the field-assisted injection of majority carriers (holes) and minority carriers (electrons) at the contacts and field-assisted barrier crossing, both obeying Fowler–Nordheim-type relations. Charge recombination at the internal interface is considered as the dominant source for electroluminescence. Accumulation of majority carriers at that interface causes an enhancement of the cathodic electric field giving rise to enhanced electron injection. This effect tends to compensate for imbalanced injection due to different energy barriers at the contacts and causes an increase of the luminescence yield as compared to single-layer LEDs. The model is able to predict (i) the redistribution of the electric field inside the LED, (ii) the field dependence of the cell current, (iii) the dependence of the steady state luminescence intensity, (iv) the luminescence yield as a function of the cell current, and (v) the characteristic rise time of the light output, each parametric in the cathodic and the interfacial energy barriers normalized to the energy barrier for hole injection. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 967-972 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Tail broadening of nondispersive photocurrent transients has been measured in 1,1-bis(di-4-tolylaminophenyl)cyclohexane-doped polystyrene over a range of concentrations, fields, and temperatures. The results are described by the parameter W, defined as W=(t1/2−t0)/t1/2, where t1/2 is the time for the transient to decay to one-half of its plateau value and t0 the time defined by the intersection of asymptotes of the plateau and trailing edge of the transient. The interpretation of the experimental results leads to the conclusion that energetic disorder is the principal source of broadening of the transients.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 8276-8281 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Hole mobilities have been measured in vapor deposited films of 1,1-bis(di-4-tolylaminophenyl)cyclohexane over an extended range of fields and temperatures. At 295 K, the mobility is approximately 10−2 cm2/V s, the highest value for a disordered molecular solid reported thus far. Monte Carlo simulations of random walk in a geometrically and energetically disordered medium demonstrate that the time dependence of the photocurrent and the field and temperature dependencies of the mobility can be described quantitatively in terms of the inherent disorder and its effect on charge transport. No polaronic or trapping phenomena need to be invoked to reproduce even subtle features of the experimental results.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Spectral, field, and temperature dependencies of steady-state photoconductivity were studied in thin films of pure phenyl substituted copolymeric polyphenylenevinylene (PhPPV) and PhPPV doped by trinitrofluorenone. The films were sandwiched between indium tin oxide (ITO) and aluminum as well as between two aluminum contacts. Typical surface extrinsic carrier photogeneration was observed in ITO/PhPPV/Al samples with positively biased ITO while the intrinsic photoconductivity dominated in Al/PhPPV/Al samples and ITO/PhPPV/Al sandwiches with negatively biased ITO. Charge carrier photogeneration in both doped and undoped PhPPV at higher photon excess energies was found to be in good agreement with predictions of the hot exciton dissociation model. At low excess photon energy of the inducing light, carrier photogeneration is ascribed to dissociation of optical excitations on charge transfer centers which are either dopant molecules in the doped samples or intrinsic defects in the pure material. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 110 (1999), S. 9214-9222 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The charge carrier mobility in a ladder-type poly(paraphenylene) (MeLPPP) and a phenylamino-substituted poly(phenylenevinylene) (PPV) derivative (PAPPV) has been studied in detail by using the time-of-flight (TOF) method. In most cases, the TOF signals feature characteristics of nondispersive charge transport in terms of the disorder formalism, although the transition from nondispersive to the dispersive transport regime was observed in PAPPV. Hole mobilities in the range of 10−4 to 7×10−3 cm2/Vs were obtained, depending on electric field and temperature. The influence of disorder on charge transport of the investigated conjugated polymers is discussed. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 6963-6967 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Diodes consisting of a hole transporting layer containing tri-stilbeneamine as active medium and a hole blocking layer (an oxadiazole blend) sandwiched between indium-tinoxide and aluminium electrodes have been characterized via both their j(F) characteristics and the dependence of intensity, quantum efficiency, and spectrum of the electroluminescence on the thickness Le of the hole blocking layer. The results are discussed within the framework of the analytic model advanced in the preceding paper. Both the decrease of the effect of electric field screening at the anode due to the space charge accumulation at the internal interface as well as the recombination efficiency with decreasing Le is in good agreement with theory. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 6954-6962 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A previously developed analytic model for charge carrier recombination in bilayer organic light emitting diodes [D. V. Khramtchenkov, V. I. Arkhipov, and H. Bässler, J. Appl. Phys. 79, 9283 (1996)] in which charge transport across the interface between anodic and cathodic cell compartments is impeded by energy barriers is extended to cells of arbitrary thickness of the constituent layers and variable energy barriers. The results indicate that the recombination yield is the result of a complicated interplay between redistribution of the electric field affecting the injection at the electrodes, internal charge accumulation, and field assisted barrier crossing. Unit charge carrier recombination efficiency is predicted to occur at moderate cell voltages and electron injection barriers less than (approximate)0.4 eV. At higher voltages, leakage process across the interface becomes progressively important. With increasing electron-injection barrier, that injection process becomes rate limiting. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 3848-3850 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A previous Monte Carlo simulation for hopping injection into a random organic dielectric has been extended to include the effect of tunneling through a thin inorganic insulator. The effect of the interface has been explained upon the fact that the attenuation length of an electron is much larger in a strongly bonded inorganic solid as compared to a van-der-Waals bonded organic. Depending upon the system parameters, significant improvement of injection is predicted. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 2933-2935 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on stimulated emission from a solid conjugated methyl-substituted ladder-type poly(paraphenylene). The threshold for stimulated emission as well as the spectral narrowing is measured. Upon exciting within the low energy tail of the S1-S0 (0–0) absorption band narrow emission lines offset from the excitation by the energies of the dominant vibrational modes are observed. From these measurements we conclude that vibronic sublevels play a major role in the optical gain mechanism. Hence, the gain mechanism can be explained in terms of molecularly excited states. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...