Regensburg 2007 – wissenschaftliches Programm

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SYOE: Symposium Organic Thin Film Electronics: From Molecular Contacts to Devices

SYOE 8: Poster Session SYOE

SYOE 8.39: Poster

Dienstag, 27. März 2007, 18:00–20:00, Poster B

High charge carrier mobility in organic semiconductor diphenylanthracene (DPA) — •Ashutosh Tripathi and Jens Pflaum — 3. Physikalisches Institut, Pfaffenwaldring 57, Universität Stuttgart, 70550 Stuttgart

In this work we focus on the growth and the electronic properties of the organic semiconductor 9,10-diphenylanthracene (DPA). DPA consists of two phenyl groups attached at the opposite (9,10)-positions of the anthracene backbone and may be considered similar to rubrene, which shows high field-effect mobility in its (ab)-plane crystal surface. Advantageously, DPA has a substantially low vapor pressure at RT, has a relatively high melting point (≈ 430K) and is thermally stable upon melting.
We have grown DPA single crystals from zone-refined material and analyzed their temperature dependent electronic transport behavior. These ultra-pure single crystals exhibit both electron and hole transport. The high charge carrier mobilities measured by Time-of-Flight (TOF) at RT for electrons (≈ 13 cm²/Vs) and holes (≈ 3.7 cm²/Vs) make this material a prominent candidate for ambipolar device applications if one overcomes the barrier for charge carrier injection occurring at the metal-DPA-interface. The mobility behavior of holes follows a band-like transport in the high temperature regime (200K - 400K). Assuming a pure band-like conduction in the low temperature regime, the saturation of the mobility yields a valence bandwidth of the order of 2 meV, which demands for a more sophisticated approach to describe the electronic behavior of DPA.