Matthias Schober

Publications (2)7.69 Total impact

• Article: Improvement of voltage and charge balance in inverted top-emitting organic electroluminescent diodes comprising doped transport layers by thermal annealing

  Michael Thomschke, Simone Hofmann, Selina Olthof, Merve Anderson, Hans Kleemann, Matthias Schober, Bjoern Luessem, Karl Leo
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  ABSTRACT: We present investigations of top emitting organic light emitting devices (OLED) comprising n- and p-doped organic charge transport layers. It has been found previously that in comparison to noninverted p-i-n OLEDs, inverted n-i-p OLEDs show reduced device performances after fabrication. These differences can be eliminated by subsequent thermal annealing of the whole n-i-p OLED. After this process, the n-i-p OLED exhibits a superior low driving voltage of 2.9 V at 1000 cd/m(2) and shows an increase in external quantum efficiency from 11% to almost 15% which we ascribe to a modified charge balance within the intrinsic organic emission layer. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3559847]
  Applied Physics Letters 12/2011; 98:083304. · 3.84 Impact Factor
• Article: Single carrier devices with electrical doped layers for the characterization of charge-carrier transport in organic thin-films

  Matthias Schober, Selina Olthof, Mauro Furno, Bjoern Luessem, Karl Leo
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  ABSTRACT: We introduce single-carrier devices with electrical doped layers as a concept for the characterization of charge-carrier transport in organic semiconductors. In this approach, individual organic layers from a multilayer device are investigated in single-carrier test devices, where they are enclosed by symmetrically arranged electrical doped layers of equal thickness and composition. Single carrier devices without electrical doped layers are usually difficult to interpret due to an uncertainty about interface dipole effects between the metal contacts and pristine organic layers. In comparison, our devices show Ohmic contacts at the electrodes as well as zero built-in voltage and thus allow a more direct insight into charge-carrier transport. State-of-the-art simulation models are applied to analyze current-voltage characteristics and evaluate crucial parameters such as energy barriers between adjacent organic layers and mobilities. © 2010 American Institute of Physics.
  Applied Physics Letters 12/2010; 97(1):013303. · 3.84 Impact Factor