Dresden 2006 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 23: POSTER Functional Organic Thin Films

CPP 23.24: Poster

Thursday, March 30, 2006, 17:00–19:00, P2

Analysis of pentacene-OFET characteristics by a modified a-Si-model — •Susanne Scheinert¹ and Gernot Paasch² — ¹TU Ilmenau — ²IFW Dresden

Measured current characteristics of pentacene OFETs depend strongly on the silanisation process [1]. Traps can be the reason for such peculiarities in organic field-effect transistors (OFET) and often the so-called a-Si-model is the appropriate one. We have investigated whether it is possible to describe the measurements with this model. Numerical two-dimensional simulations have been carried out with a systematic variation of interface and bulk trap parameters. Comparison with the measured curves shows, that both donor-like and acceptor-like traps near the valence band have to be supposed to describe the measurements. However, with a high trap concentration in a narrow distribution one obtains the same current characteristics, including the temperature dependence, as with a lower concentration and a broader distribution. Moreover, in addition also distributed interface traps have to be taken into account to obtain a satisfactory description of the experimental current characteristics. Even though the characteristics can be described well, a unique extraction of trap parameters solely from transistor current characteristics is not possible.

[1] 1 K.P. Pernstich, S. Haas, D. Oberhoff, C. Goldmann, D.J. Gundlach, B. Batlogg, A.N. Rashid, G. Schitter, J. Appl. Phys. 96 (2004) 6431.