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FIZIKA A 14 (2005) 2, 167 - 178
 
CURRENT FILAMENTATION AND DEGRADATION IN ELECTRONIC DEVICES BASED ON
AMORPHOUS ORGANIC LAYERS
EDUARD TUTIŠ a and IVO BATISTIĆ b
aInstitute of Physics, Bijenička cesta 46, P.O. Box 304,
HR-10 000 Zagreb, Croatia
bDepartment of Physics, University of Zagreb, Bijenička cesta 32, P.O. Box 331
HR-10 002 Zagreb, Croatia
Received 15 March 2005; revised manuscript received 21 July 2005
Accepted 19 September 2005 Online 18 November 2005
The recent advent of new flat-panel organic displays follows a long struggle for the
extended device lifetime. Many modifications proposed along this way have been based on
trial and error experimentation. In this paper, we show that some recent major
improvements may have been implicitly related to fighting against the strong current
filamentation, intrinsic for charge injection and conduction in organic amorphous thin
films. We first recapitulate some major causes of current filamentation in thin amorphous
organic layers. Then we consider the charge transport in devices with a high-mobility
injection layer, with a smoothened organic heterojunction surface, that operate at lower
electric fields, and the devices with doped transport layers. We show that these
conditions, known to decrease the device degradation rates, may separately lead to the
current homogenization in organic films.
PACS numbers: 73.50.-h, 73.40.Ns, 73.61.Ph
UDC 538.935
Keywords: organic-molecular devices, light-emitting diodes, filamentation, numerical
simulations, degradation, ageing
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