Gradual Controlling the Work Function of Metal Electrodes by Water Dissolved Mixed Interlayers for Ambipolar Polymer Field-Effect Transistors

We report on high-performance organic field-effect transistors (OFETs) with low-cost Mo source/drain electrode by water base solution-processed hybrid PEI:V₂O₅ interlayers. We were success control of the metal electrode’s work function (W_f ) by ratio of mixture of contact interlayers and obtain the work function of the Mo electrodes progressively changed from 4.16 to 4.9 eV to reduce energy barriers of ambipolar semiconductor. With the insertion of the mixed layer, OFETs gained significantly improved performance for ambipolar 3,6-Bis-(5bromo-thiophen-2-yl)-N,N-bis (2-octyl-1-dodecyl)-1,4-dioxo-pyrrolo[3,4-c]pyrrole (DPPT-TT) polymer semiconductors, OFETs on the basis DPPT-TT with hybid mixed interlayer/Mo electrodes exhibit field-effect mobilities of 0.8 and 1.9 cm²/Vs for electron and hole mobility, respectively.