Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 14: Poster I
HL 14.43: Poster
Montag, 24. März 2003, 17:00–19:30, HSZ/P2
Hole transport and trapping in binary triphenyldiamine mixtures — •Claus Jäger1, Dietrich Haarer1, and Mukundan Thelakkat2 — 1Experimentalphysik IV, Universität Bayreuth, 95447 Bayreuth — 2Makromolekulare Chemie I, Universität Bayreuth, 95447 Bayreuth
Charge carrier trapping in organic transport materials used for light emitting diodes or solar cells is still not fully understood. In our studies we generated defined trapping states with varying depths by preparing different binary mixtures of low molecular weight hole transport materials (TPDs) with different HOMO levels. The transport properties were investigated by the time-of-flight (TOF) technique, where a short laser pulse of strongly absorbed light generates a delta shaped charge distribution. The charges travel in an applied external electrical field through the bulk material and are slowed down by the traps. From the decay of the measured current one can determine the mobility and trapping properties of the material. A large variation of the mobility can be seen even for small trap concentrations. The results will be discussed in the frame of a known standard model developed for molecularly doped polymers.