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Manuscript Title: MOLED: simulation of multilayer organic light emitting diodes.
Authors: H. Houili, E. Tutis, H. Lutjens, M.N. Bussac, L. Zuppiroli
Program title: MOLED
Catalogue identifier: ADSG
Journal reference: Comput. Phys. Commun. 156(2003)108
Programming language: Fortran 90.
Computer: DEC Alpha, Pentium 4.
Operating system: UNIX, LINUX.
RAM: 250K words
Word size: 64
Keywords: Organic semiconductor, Diode, Image force, hopping conductivity, carrier injection, Langevin recombination, Solid state physics, Other.
Classification: 7.7.

Nature of problem:
Injection of electrons and holes into an organic electroluminescent material occurs through tunneling from metal electrodes. The transport of carriers inside the molecular medium proceeds by hopping from one molecule to another. The emission of light is a result of their radiative Langevin recombination.

Solution method:
The equations governing the time evolution of current, charge density and electric field in the device are solved after discretization in time. An implicit procedure is used to perform the time step. The non-linear effects, originating from strong dependence of the hopping frequency on charge distribution, are treated within the first order in the implicit method. The molecular energy levels are updated at each time step to take into account the Coulomb interactions.

Unusual features:
This code has a GUI interface for input/output that can be obtained from the URL: http://lomm.epfl.ch/.

Running time:
A typical calculation takes a few minutes on DEC Alpha 500MHz or Pentium 4 1.8GHz machines. The execution time may vary considerably, depending on the complexity of the problem.