Insight into the contact resistance problem by direct probing of the potential drop in organic field-effect transistors

摘要

The microscopic electric field induced second-harmonic generation technique is used for directnobservation of electric field profiles and evaluation of the potential drop on the injection electrodenin the organic field-effect transistors with various channel lengths L. It is found that the potentialndrop on injection electrode is not a function of L. We show that the analysis of the transmission linenmodel u0002TLMu0003 cannot distinguish channel length independent contact resistance and potential drop.nTracing back to the conceptional idea of contact resistance proposed by Shockley in 1964, the TLMnapproach is discussed to explain L-dependent contact resistance. © 2010 American Institute ofnPhysics. u0004doi:10.1063/1.3533020